JP2021138161A - Vehicle suspension member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension member for a vehicle having excellent dimensional accuracy, particularly dimensional accuracy of a bolt hole position.
SOLUTION: The suspension member (10) for a vehicle including an injection molded body made of a thermoplastic resin composition, and the suspension member (10) for the vehicle is provided with a bolt hole (22) for connecting to other parts. The arm portion (32) is provided, and the thickness (32d) of the arm portion is less than 20 mm. The thickness (32d) of the arm portion is preferably 5 mm or more.
[Selection diagram] Fig. 2

Description

The present invention relates to a vehicle suspension member.

In recent years, in the field of transportation equipment including automobiles and aircraft, weight reduction of parts has been promoted for the purpose of improving fuel efficiency. In order to reduce the weight of parts, it is being considered to use a resin material instead of the current metal material for the material of each part. For example, by using the thermoplastic resin composition as a molding material for a frame-based member, a suspension member, a shock absorbing member, etc. for an automobile, an automobile that is lighter than the current product can be obtained.

Of these, the suspension member is mainly manufactured by integrally casting a light alloy or by welding and assembling a steel plate (Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-69962

The suspension (that is, the suspension device) has a function as a shock absorber that does not transmit the unevenness of the road surface to the vehicle body, a function of positioning the wheels / axles, and a function of pressing the wheels against the road surface, thereby improving ride comfort and steering stability. Improve.

Among the components of the suspension, the suspension member having an arm portion provided with bolt holes for connecting to other parts such as an upright for a racing car, a suspension arm, a hub carrier for a passenger car, and a knuckle has excellent dimensions. Accuracy, especially excellent dimensional accuracy of bolt hole positions, is required.

However, when a thermoplastic resin composition is used as a molding material for a suspension member for a vehicle instead of the current metal material, the problem is that the thermoplastic resin composition has a larger shrinkage change during molding than the metal material. Become.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a suspension member for a vehicle having excellent dimensional accuracy, particularly dimensional accuracy of bolt hole positions.

The present invention has the following aspects.

[1] A vehicle suspension member including an injection molded product made of a thermoplastic resin composition.
The vehicle suspension member has an arm portion provided with bolt holes for connecting to other parts.
A vehicle suspension member having an arm portion having a thickness of less than 20 mm.

[2] The vehicle suspension member according to the above [1], wherein the thickness of the arm portion is 5 mm or more.
[3] The vehicle suspension member according to the above [1] or [2], wherein the thermoplastic resin composition contains a liquid crystal polyester.

[4] The vehicle suspension member according to any one of the above [1] to [3], wherein the vehicle suspension member is an upright having a central hole for receiving a wheel bearing.
[5] The vehicle suspension member according to the above [4], wherein a gate mark continuous on the entire circumference in the circumferential direction is provided on the inner peripheral surface of the central hole.

[6] The vehicle suspension member according to any one of [1] to [5] above, wherein the thermoplastic resin composition contains an inorganic filler.
[7] The vehicle suspension member according to the above [6], wherein the inorganic filler is a fibrous filler.
[8] The vehicle suspension member according to the above [7], wherein the fibrous filler is carbon fiber.

According to the present invention, it is possible to provide a suspension member for a vehicle having excellent dimensional accuracy, particularly dimensional accuracy of bolt hole positions.

It is a front view which shows the front upright of 1st Embodiment which concerns on this invention. FIG. 5 is a cross-sectional view taken along the line II of FIG. It is a back view of the front upright of the first embodiment. It is a schematic perspective view of the front upright of 1st Embodiment. It is a schematic diagram which shows that the front upright of 1st Embodiment is connected with an upper arm, a lower arm and a brake caliper. It is a schematic perspective view which shows the knuckle of the 2nd Embodiment. It is a schematic perspective view which shows the knuckle of another aspect of 2nd Embodiment. It is a schematic perspective view which shows the knuckle of another aspect of 2nd Embodiment. It is a graph which shows the maximum change amount of the tip of an arm part with respect to the thickness of an arm part. It is a graph which shows the maximum change amount of the tip of an arm part with respect to the thickness of an arm part. It is a graph which shows the maximum change amount of the tip of an arm part with respect to a gate position. It is a graph which shows the ratio of each maximum change amount to the maximum change amount which provided the gate position which is continuous in the whole circumference in the circumferential direction on the inner peripheral surface of a central hole with respect to the gate position. It is a schematic diagram which shows the method of the intensity test of an upright.

Hereinafter, a vehicle suspension member according to an embodiment to which the present invention is applied will be described in detail. In addition, in the drawings used in the following description, in order to make the features easy to understand, the featured parts may be enlarged for convenience, and the dimensional ratio of each component may not be the same as the actual one. No.

<< Vehicle suspension members >>
The vehicle suspension member of the present embodiment is a vehicle suspension member including an injection molded body made of a thermoplastic resin composition, and has an arm portion provided with bolt holes for connecting to other parts. The thickness of the arm portion is less than 20 mm.

The vehicle suspension member is not limited as long as it is a member included in the vehicle suspension device and has an arm portion provided with bolt holes for connecting to other parts. For example, it can be applied to uprights for racing cars, suspension arms, hub carriers for passenger cars, knuckles, and the like.

[First Embodiment]
Hereinafter, a front upright will be described as an example of the vehicle suspension member of the present invention with reference to the drawings.

FIG. 1 is a front view showing a front upright of a first embodiment according to a vehicle suspension member of the present invention. FIG. 2 is a cross-sectional view taken along the line II of FIG. FIG. 3 is a back view of the front upright of the first embodiment. FIG. 4 is a schematic perspective view of the front upright of the first embodiment.

The front upright 10 of the first embodiment is located below the main body 45 provided with the central hole 40 for receiving the wheel bearing, the arm portions 30, 31, 32, 33 for connecting to the brake caliper, and the main body 45. The lower arm connecting portion 50 and the upper arm connecting portion 60 are provided above the main body portion 45. Bolt holes 20, 21, 22, 23 for connecting to the brake caliper as other parts are provided in the arm portions 30, 31, 32, 33, respectively. Bolt holes 20, 21, 22, and 23 are holes into which bolts can be inserted. Nuts may be attached to the bolt holes 20, 21, 22, 23.

The front upright 10 of the first embodiment is an integrally molded body formed by injection molding a thermoplastic resin composition composed of 30% by mass of PAN-based carbon fiber and 70% by mass of liquid crystal polyester. The thermoplastic resin composition is not particularly limited. Suitable thermoplastic resin compositions will be described later.

The front upright 10 of the first embodiment is an integrally molded body in which the main body portion 45, the arm portions 30, 31, 32, 33, the lower arm connecting portion 50, and the upper arm connecting portion as a whole are made of a thermoplastic resin composition. Is. The front upright is not limited as long as it includes an injection molded product made of a thermoplastic resin composition. The front upright is preferably an integrally molded body in which at least the arm portions 30, 31, 32, 33 and the main body portion 45 are injection-molded with a thermoplastic resin composition, and the arm portion 30 which is an integrally molded body. , 31, 32, 33 and the main body 45 may be attached with the lower arm connecting portion 50 and the upper arm connecting portion 60.

The thickness of the arm portions 30, 31, 32, 33 for connecting the front upright 10 of the first embodiment to the brake caliper is 13 mm. Since the thickness 30d of the arm portion 30 is less than 20 mm, the maximum amount of deformation of the arm portions 30, 31, 32, 33 for connecting to the brake caliper when the front upright 10 of the first embodiment is injection-molded. Can be made smaller. The thickness 30d of the arm portion 30 is less than 20 mm, preferably 18 mm or less, more preferably 16 mm or less, and further preferably 15 mm or less. Similarly, the thickness 31d of the arm portion 31, the thickness 32d of the arm portion 32, and the thickness 33d of the arm portion 33 are less than 20 mm, preferably 18 mm or less, and more preferably 16 mm or less. It is more preferably 15 mm or less. These findings were obtained from the results of a simulation of plastic injection molding, which will be described later.

That is, by reducing the thickness 30d of the arm portion 30, the dimensional change from the mold size can be reduced, so that the injection molded body of the front upright 10 can be stably mass-produced with the target dimensional accuracy. The dimensional accuracy between the central hole 40 that receives the wheel bearing and the bolt holes 20, 21, 22, 23 for connecting the brake caliper can be improved.

The front upright 10 of the first embodiment has a plurality of arm portions provided with bolt holes for connecting to other parts. When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is, depending on the purpose. Is preferably less than 20 mm, the thickness of at least two arm portions is more preferably less than 20 mm, and the thickness of all arm portions is even more preferably less than 20 mm.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 18 mm or less. It is preferable that the thickness of at least two arm portions is 18 mm or less, and it is further preferable that the thickness of all the arm portions is 18 mm or less.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 16 mm or less. It is preferable that the thickness of at least two arm portions is 16 mm or less, and it is further preferable that the thickness of all the arm portions is 16 mm or less.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 15 mm or less. It is preferable that the thickness of at least two arm portions is 15 mm or less, and the thickness of all arm portions is further preferably 15 mm or less.

The arm portions 30, 31, 32, 33 for connecting to the brake caliper are required to have strength and rigidity in addition to dimensional accuracy. Conventional uprights for racing cars have been made of metal materials such as iron and aluminum alloys. Since the front upright 10 of the first embodiment is formed of a thermoplastic resin composition containing PAN-based carbon fibers and liquid crystal polyester, it can have the same strength and rigidity as conventional uprights.

The thickness 30d of the arm portion 30 is preferably 5 mm or more, more preferably 6 mm or more, and further preferably 7 mm or more, because the strength and rigidity of the front upright 10 and the arm portion 30 can be ensured. preferable. Similarly, the thickness 31d of the arm portion 31, the thickness 32d of the arm portion 32, and the thickness 33d of the arm portion 33 are preferably 5 mm or more, more preferably 6 mm or more, and 7 mm or more. Is even more preferable.

The thickness 30d of the arm portion 30 is preferably 5 mm or more and less than 20 mm, more preferably 6 mm or more and 18 mm or less, further preferably 7 mm or more and 16 mm or less, and particularly preferably 7 mm or more and 15 mm or less. preferable. Similarly, the thickness 31d of the arm portion 31, the thickness 32d of the arm portion 32, and the thickness 33d of the arm portion 33 are preferably 5 mm or more and less than 20 mm, more preferably 6 mm or more and 18 mm or less, and 7 mm. It is more preferably 16 mm or more, and particularly preferably 7 mm or more and 15 mm or less.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 5 mm or more. It is preferable that the thickness of at least two arm portions is 5 mm or more, and it is further preferable that the thickness of all the arm portions is 5 mm or more.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 6 mm or more. It is preferable that the thickness of at least two arm portions is 6 mm or more, and it is further preferable that the thickness of all the arm portions is 6 mm or more.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 7 mm or more. It is preferable that the thickness of at least two arm portions is 7 mm or more, and it is further preferable that the thickness of all the arm portions is 7 mm or more.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 5 mm or more and less than 20 mm. It is more preferable that the thickness of at least two arm portions is 5 mm or more and less than 20 mm, and it is further preferable that the thickness of all the arm portions is 5 mm or more and less than 20 mm.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 6 mm or more and 18 mm or less. It is more preferable that the thickness of at least two arm portions is 6 mm or more and 18 mm or less, and it is further preferable that the thickness of all the arm portions is 6 mm or more and 18 mm or less.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 7 mm or more and 16 mm or less. It is more preferable that the thickness of at least two arm portions is 7 mm or more and 16 mm or less, and it is further preferable that the thickness of all the arm portions is 7 mm or more and 16 mm or less.

When the vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, the thickness of at least one of the plurality of arm portions is 7 mm or more and 15 mm or less. It is more preferable that the thickness of at least two arm portions is 7 mm or more and 15 mm or less, and it is further preferable that the thickness of all the arm portions is 7 mm or more and 15 mm or less.

The thickness of the arm portion provided with bolt holes for connecting to other parts can be measured using a caliper.

The main body 45 of the front upright 10 has a central hole 40 for receiving the wheel bearing near the center of the entire front upright 10. The main body 45 of the front upright 10 is provided with a continuous gate mark on the inner peripheral surface of the central hole 40 on the entire circumference in the circumferential direction. As will be described later, rather than an injection molding method in which a gate position is provided at the end of the front upright 10, an injection in which a continuous gate position is provided on the inner peripheral surface of the central hole 40 of the front upright 10 over the entire circumference in the circumferential direction. By adopting the molding method, it is possible to reduce the amount of deformation of the arm portion provided with the bolt holes for connecting to the brake caliper. When a gate position continuous on the entire circumference in the circumferential direction is provided on the inner peripheral surface of the central hole 40, a gate mark continuous on the entire circumference in the circumferential direction is formed on the inner peripheral surface of the central hole 40.

FIG. 5 is a schematic view showing that the front upright of the first embodiment is connected to the upper arm, the lower arm and the brake caliper. The upper arm connecting portion of the front upright 10 is connected to the upper arms 61 and 62, and the lower arm connecting portion is connected to the lower arms 51 and 52. The front upright 10 is connected to the brake caliper 70 via the bolt hole. Since the front upright 10 is an injection molded product made of a thermoplastic resin composition, it has appropriate rigidity and is excellent in dimensional accuracy, particularly dimensional accuracy of bolt hole positions, and is therefore suitable as a suspension member for vehicles. ..

The lower arm connecting portion 50 and the upper arm connecting portion 60 of the front upright 10 of the first embodiment are also required to have strength and rigidity. In particular, the lower arm connecting portion 50 is a portion of the front upright 10 where stress is most concentrated. Since the front upright 10 of the first embodiment is formed of a thermoplastic resin composition containing PAN-based carbon fibers and liquid crystal polyester, it can have sufficient strength and rigidity.

<Thermoplastic resin composition>
[Second Embodiment]
FIG. 6 is a schematic perspective view showing a knuckle 11 for a passenger car according to a second embodiment of the suspension member for a vehicle. In the drawings after FIG. 6, the same components as those shown in the already explained figures are designated by the same reference numerals as in the case of the already explained figures, and detailed description thereof will be omitted.

The knuckle 11 of the second embodiment has a main body portion 45 provided with a central hole 40 for receiving the wheel bearing, and arm portions 30 and 32 for connecting to the brake caliper, and the respective arm portions 30. , 32 are provided with bolt holes 20 and 22 for connecting to a brake caliper as another component.

As the knuckle 11 of the second embodiment, a molded product obtained by injection molding a thermoplastic resin composition composed of 30% by mass of PAN-based carbon fibers and 70% by mass of liquid crystal polyester can be obtained. By making the thickness 30d of the arm portion 30 less than 20 mm, it is possible to reduce the dimensional change from the mold dimensions during injection molding, and the bolt for connecting the central hole 40 that receives the wheel bearing and the brake caliper. The dimensional accuracy between the holes 20 and 22 can be improved. By setting the thickness of the arm portion 30d to 5 mm or more, good strength of the knuckle 11 and the arm portion 30 can be ensured. Since the knuckle 11 is an injection molded product made of a thermoplastic resin composition, it has appropriate rigidity and is excellent in dimensional accuracy, particularly dimensional accuracy of bolt hole positions, and is therefore suitable as a suspension member for vehicles.

FIG. 7 is a schematic perspective view showing a knuckle 12 of another aspect of the second embodiment relating to the suspension member for a vehicle.

The knuckle 12 also has a main body portion 45 provided with a central hole 40 for receiving the wheel bearing, and arm portions 30 and 32 for connecting to the brake caliper. Bolt holes 20 and 22 for connecting to a brake caliper as another component are provided.

As the knuckle 12, a molded product obtained by injection molding a thermoplastic resin composition composed of 30% by mass of PAN-based carbon fibers and 70% by mass of polyether sulfone (PES) can be obtained. By making the thickness 30d of the arm portion 30 less than 20 mm, it is possible to reduce the dimensional change from the mold dimensions during injection molding, and the bolt for connecting the central hole 40 that receives the wheel bearing and the brake caliper. The dimensional accuracy between the holes 20 and 22 can be improved. By setting the thickness 30d of the arm portion 30 to 5 mm or more, the strength of the knuckle 12 and the arm portion 30 can be ensured. Since the knuckle 12 is an injection molded product made of a thermoplastic resin composition, it has appropriate rigidity and is excellent in dimensional accuracy, particularly dimensional accuracy of bolt hole positions, and is therefore suitable as a suspension member for vehicles.

FIG. 8 is a schematic perspective view showing a knuckle 13 of another aspect of the second embodiment relating to the suspension member for a vehicle.

The knuckle 13 also has a main body portion 45 provided with a central hole 40 for receiving the wheel bearing, and arm portions 30 and 32 for connecting to the brake caliper. Bolt holes 20 and 22 for connecting to a brake caliper as another component are provided.

The knuckle 13 can be a molded product obtained by injection molding a thermoplastic resin composition composed of 30% by mass of PAN-based carbon fibers and 70% by mass of polyether sulfone (PES). By making the thickness 30d of the arm portion 30 less than 20 mm, it is possible to reduce the dimensional change from the mold dimensions during injection molding, and the bolt for connecting the central hole 40 that receives the wheel bearing and the brake caliper. The dimensional accuracy between the holes 20 and 22 can be improved. By setting the thickness 30d of the arm portion 30 to 5 mm or more, the strength of the knuckle 13 and the arm portion 30 can be ensured. Since the knuckle 13 is an injection molded product made of a thermoplastic resin composition, it has appropriate rigidity and is excellent in dimensional accuracy, particularly dimensional accuracy of bolt hole positions, and is therefore suitable as a suspension member for vehicles.

[Third Embodiment]
The vehicle suspension member is not limited to the front upright of the first embodiment and the knuckle of the second embodiment as long as it has an arm portion provided with bolt holes for connecting to other parts, and is for vehicles. Of the suspension members, it can also be applied to other members.

For example, a suspension arm can be mentioned as a third embodiment of the suspension member for a vehicle.
The suspension arm of the third embodiment has an arm portion provided with a bolt hole for connecting to an upright as another component, and the thickness of the arm portion is less than 20 mm.

The suspension arm of the third embodiment may be the lower arms 51 and 52 shown in FIG. 5, and may be the upper arms 61 and 62. The lower arms 51 and 52 and the upper arms 61 and 62 are one of the suspension members for a vehicle, which are connected to the vehicle body and control the movement of the tires.

As the suspension arm of the third embodiment, a molded body obtained by injection molding a thermoplastic resin composition composed of 30% by mass of PAN-based carbon fiber and 70% by mass of liquid crystal polyester can be obtained. When the thickness of the arm portion is less than 20 mm, the dimensional change from the mold size can be reduced during injection molding, and the dimensional accuracy of the suspension arm, particularly the dimensional accuracy of the bolt hole position can be improved. By setting the thickness of the arm portion to 5 mm or more, good strength of the suspension arm and the arm portion can be ensured. Since the suspension arm of the third embodiment is an injection molded body made of a thermoplastic resin composition, it has appropriate rigidity and is excellent in dimensional accuracy, particularly dimensional accuracy of bolt hole positions. Is suitable as.

(Thermoplastic resin composition)
The thermoplastic resin composition is not limited as long as it forms an injection molded product. The thermoplastic resin composition preferably contains a thermoplastic resin and an inorganic filler.

-Thermoplastic resin Examples of the thermoplastic resin contained in the thermoplastic resin composition include polyolefin resins such as liquid crystal polyester, polyethylene, polypropylene, polybutadiene and polymethylpentene, vinyl chloride, vinylidene chloride and vinyl such as polyvinyl alcohol. Polyamide-based resins, polystyrenes, polystyrene-based resins such as acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin), polyamide 6 (nylon 6), polyamide 66 (nylon 66), polyamide 11 (nylon 11) , Polyamide 12 (Nylon 12), Polyamide 46 (Nylon 46), Polyamide 610 (Nylon 610), Polytetramethylene terephthalamide (Nylon 4T), Polyhexamethylene terephthalamide (Nylon 6T), Polymethaxylylene adipamide (Nylon) Polyamide-based resins such as MXD6), polynonamethylene terephthalamide (nylon 9T), polydecamethylene terephthalamide (nylon 10T), polyesters other than liquid crystal polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polytrimethylene terephthalate. Polysulfone resins such as based resins, modified polysulfones, polyether sulfones, polysulfones, polyphenylsulfones, linear polyphenylene sulfides, crosslinked polyphenylene sulfides, semi-crosslinked polyphenylene sulfides and other polyphenylene sulfide resins, polyether ketones, polyethers. Examples thereof include polyether ketone resins such as ether ketone and polyether ketone ketone, polyimide resins such as thermoplastic polyimide, polyamideimide and polyetherimide, and thermoplastic resins such as polycarbonate and polyphenylene ether. Of these, liquid crystal polyester or polyether sulfone is preferable.

-Liquid crystal polyester The liquid crystal polyester used in the present embodiment preferably exhibits liquid crystal properties in a molten state, and the thermoplastic resin containing the liquid crystal polyester also preferably exhibits liquid crystal properties in a molten state, and melts at a temperature of 450 ° C. or lower. Is preferable.
The liquid crystal polyester used in the present embodiment may be a liquid crystal polyester amide, a liquid crystal polyester ether, a liquid crystal polyester carbonate, or a liquid crystal polyester imide. The liquid crystal polyester used in the present embodiment is preferably a fully aromatic liquid crystal polyester using only an aromatic compound as a raw material monomer.

A typical example of the liquid crystal polyester used in the present embodiment is at least one compound selected from the group consisting of aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic hydroxyamine and aromatic diamine. Is selected from the group consisting of a compound obtained by polymerizing (hypercondensing), a compound obtained by polymerizing a plurality of kinds of aromatic hydroxycarboxylic acids, an aromatic dicarboxylic acid and an aromatic diol, an aromatic hydroxyamine and an aromatic diamine. Examples thereof include those obtained by polymerizing at least one compound, and those obtained by polymerizing a polyester such as polyethylene terephthalate and an aromatic hydroxycarboxylic acid. Here, the aromatic hydroxycarboxylic acid, the aromatic dicarboxylic acid, the aromatic diol, the aromatic hydroxyamine, and the aromatic diamine are independently used in place of a part or all of them, and a polymerizable derivative thereof is used. May be good.

Examples of polymerizable derivatives of compounds having a carboxyl group, such as aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid, are those obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group (ester), carboxyl. Examples thereof include those obtained by converting a group into a haloformyl group (acid halide) and those obtained by converting a carboxyl group into an acyloxycarbonyl group (acid anhydride). Examples of polymerizable derivatives of compounds having a hydroxyl group, such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxyamines, are those obtained by acylating a hydroxyl group and converting it to an acyloxyl group (acylated product). ). Examples of polymerizable derivatives of compounds having an amino group, such as aromatic hydroxyamines and aromatic diamines, include those obtained by acylating an amino group and converting it into an acylamino group (acylated product).

The liquid crystal polyester used in the present embodiment preferably has a repeating unit represented by the following formula (1) (hereinafter, may be referred to as "repeating unit (1)"), and the repeating unit (1) and the repeating unit (1) are used. A repeating unit represented by the following formula (2) (hereinafter, may be referred to as "repeating unit (2)") and a repeating unit represented by the following formula (3) (hereinafter, "repeating unit (3)"". It is more preferable to have (may be).

(1) -O-Ar ^1- CO-
(2) -CO-Ar ^2- CO-
(3) -X-Ar ^3- Y-

(Ar ¹ represents a phenylene group, a naphthylene group or a biphenylylene group. ^{Ar 2} and Ar ³ independently represent a phenylene group, a naphthylene group, a biphenylylene group or a group represented by the following formula (4). And Y each independently represent an oxygen atom or an imino group (-NH-). The ^{hydrogen atom in the group represented by Ar 1} , Ar ² or Ar ³ independently represents a halogen atom or an alkyl group, respectively. Alternatively, it may be substituted with an aryl group.)

(4) -Ar ^4- Z-Ar ^5-

(Ar ⁴ and Ar ⁵ independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group or an alkylidene group.)

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-hexyl group and a 2-ethylhexyl group. Examples thereof include an n-octyl group and an n-decyl group, and the number of carbon atoms thereof is preferably 1 to 10. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group and a 2-naphthyl group, and the number of carbon atoms thereof is preferably 6 to 20. When the hydrogen atom is substituted with these groups, the number is preferably 2 or less, more preferably 1 or less, independently for each of the groups represented by ^{Ar 1} , Ar ² or Ar ^3. preferable.

Examples of the alkylidene group include a methylene group, an ethylidene group, an isopropylidene group, an n-butylidene group and a 2-ethylhexylidene group, and the carbon number thereof is preferably 1 to 10.

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. As the repeating unit (1), Ar ¹ is a p-phenylene group (repeating unit derived from p-hydroxybenzoic acid), and Ar ¹ is a 2,6-naphthylene group (6-hydroxy-2). − Repeating unit derived from naphthoic acid) is preferred.
In the present specification, the term "origin" means that the chemical structure of the functional group that contributes to the polymerization changes due to the polymerization of the raw material monomer, and no other structural change occurs.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. As the repeating unit (2), Ar ² is a p-phenylene group (repeating unit derived from terephthalic acid), Ar ² is an m-phenylene group (repeating unit derived from isophthalic acid), Ar ² Is a 2,6-naphthylene group (repetitive unit derived from 2,6-naphthalenedicarboxylic acid), and Ar ² is a diphenyl ether-4,4'-diyl group (diphenyl ether-). A repeating unit derived from 4,4'-dicarboxylic acid) is preferred.

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxylamine or aromatic diamine. As the repeating unit (3), Ar ³ is a p-phenylene group (a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ is a 4,4'-biphenylylene group. (Repeat units derived from 4,4'-dihydroxybiphenyl, 4-amino-4'-hydroxybiphenyl or 4,4'-diaminobiphenyl) are preferred.

The content of the repeating unit (1) is the total amount of all repeating units (the amount equivalent to the amount of substance (mol) of each repeating unit by dividing the mass of each repeating unit constituting the liquid crystal polyester by the formula amount of each repeating unit. ) Is obtained, and the total value of these values) is preferably 30 mol% or more, more preferably 30 mol% or more and 90 mol% or less, further preferably 40 mol% or more and 80 mol% or less, and 50 mol% or more and 70. More than mol% is particularly preferable.

The content of the repeating unit (2) is preferably 35 mol% or less, more preferably 10 mol% or more and 35 mol% or less, still more preferably 15 mol% or more and 30 mol% or less, based on the total amount of all repeating units. , 17.5 mol% or more and 27.5 mol% or less are particularly preferable.

The content of the repeating unit (3) is preferably 35 mol% or less, more preferably 10 mol% or more and 35 mol% or less, still more preferably 15 mol% or more and 30 mol% or less, based on the total amount of all repeating units. , 17.5 mol% or more and 27.5 mol% or less are particularly preferable.

The higher the content of the repeating unit (1), the easier it is to improve the melt fluidity, heat resistance, strength and rigidity, but if it is too high, the melt temperature and melt viscosity tend to increase, and the temperature required for molding increases. easy.

The ratio of the content of the repeating unit (2) to the content of the repeating unit (3) is expressed by [content of repeating unit (2)] / [content of repeating unit (3)] (mol / mol). Therefore, 0.9 / 1-1 / 0.9 is preferable, 0.95 / 1-1 / 0.95 is more preferable, and 0.98 / 1-1 / 0.98 is even more preferable.

The liquid crystal polyester used in the present embodiment may have two or more repeating units (1) to (3) independently of each other. Further, the liquid crystal polyester may have a repeating unit other than the repeating units (1) to (3), but the content thereof is preferably 10 mol% or less with respect to the total amount of all the repeating units. More preferably, it is mol% or less.

The liquid crystal polyester used in the present embodiment has a repeating unit (3) in which X and Y are oxygen atoms, respectively, that is, having a repeating unit derived from a predetermined aromatic diol, that is, the melt viscosity. Is likely to be low, so it is preferable to have only those in which X and Y are oxygen atoms as the repeating unit (3), respectively.

The liquid crystal polyester used in the present embodiment is obtained by melt-polymerizing a raw material monomer corresponding to a repeating unit constituting the liquid crystal polyester and solid-phase polymerizing the obtained polymer (hereinafter, may be referred to as “prepolymer”). It is preferable to manufacture the product. As a result, a high molecular weight liquid crystal polyester having high heat resistance, strength and rigidity can be produced with good operability. The melt polymerization may be carried out in the presence of a catalyst, and examples of this catalyst include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate and antimony trioxide. , 4- (Dimethylamino) pyridine, 1-methylimidazole and the like, and the nitrogen-containing heterocyclic compound is mentioned, and the nitrogen-containing heterocyclic compound is preferably used.

The flow start temperature of the liquid crystal polyester used in the present embodiment is preferably 280 ° C. or higher, more preferably 280 ° C. or higher and 400 ° C. or lower, and further preferably 280 ° C. or higher and 380 ° C. or lower.
The higher the flow start temperature of the liquid crystal polyester used in the present embodiment, the more the heat resistance, strength and rigidity of the liquid crystal polyester tend to improve. On the other hand, when the flow start temperature of the liquid crystal polyester exceeds 400 ° C., the melting temperature and the melting viscosity of the liquid crystal polyester tend to increase. Therefore, the temperature required for molding the liquid crystal polyester tends to increase.

In the present specification, the flow start temperature of the liquid crystal polyester is also referred to as a flow temperature or a flow temperature, and is a temperature that serves as a guideline for the molecular weight of the liquid crystal polyester (edited by Naoyuki Koide, "Liquid Crystal Polymer-Synthesis / Molding / Application-". , LCD Co., Ltd., June 5, 1987, p.95). The flow start temperature is such that the liquid crystal polyester is ^{melted while raising the temperature at a rate of 4 ° C./min under a load of 9.8 MPa (100 kg / cm 2} ) using a capillary rheometer, and is melted from a nozzle having an inner diameter of 1 mm and a length of 10 mm. It is a temperature showing a viscosity of 4800 Pa · s (48000 poisons) when extruded.

The ratio of the content of the liquid crystal polyester in the thermoplastic resin composition is preferably 40% by mass or more and 100% by mass or less, and more preferably 45% by mass or more and 100% by mass or less with respect to 100% by mass of the thermoplastic resin composition. , 50% by mass or more and 100% by mass or less is more preferable, and 60% by mass or more and 100% by mass or less is particularly preferable.

-Polyester sulfone As the polyether sulfone used in the present embodiment, aromatic polysulfone is preferable. Examples of the aromatic polysulfone include resins having at least a structural unit in which a sulfonyl group (-SO _2- ), an arylene group (-Ar-) and an ether bond (-O-) are bonded in this order. ..

Examples of the resin include a compound represented by the following general formula (I) and a compound represented by the following general formula (II).

(In the formula, R ¹ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a phenyl group, or a halogen atom, and n1 is an integer of 0 to 4, and is the same or different phenylene group. each R ¹ may be the same or different, and each n1 identical or different phenylene groups may be the same or different from each other.)

（式中、Ｒ^２は炭素数１〜６のアルキル基、炭素数３〜１０のアルケニル基、フェニル基、又はハロゲン原子を表し、ｎ２は０〜４の整数であり、同一の又は異なるフェニレン基の各Ｒ^２は互いに同一でも異なっていてもよく、同一の又は異なるフェニレン基の各ｎ２は互いに同一でも異なっていてもよい。）

(In the formula, R ² represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a phenyl group, or a halogen atom, and n2 is an integer of 0 to 4, and is the same or different phenylene group. ^{Each R 2} of the same or different phenylene groups may be the same or different from each other, and each n 2 of the same or different phenylene groups may be the same or different from each other.)

Examples of commercially available products of the compound represented by the general formula (I) include Sumitomo Chemical Co., Ltd.'s trade name Sumika Excel (registered trademark) PES 3600P, 4100P and 4800P.

The reduced viscosity of the polyether sulfone is preferably more than 0.36 (dL / g) and 0.50 (dL / g) or less, and is 0.40 (dL / g) or more and 0.45 (dL / g). More preferably:
When the reducing viscosity of the polyethersulfone is equal to or greater than the above lower limit, the release of volatile components in a high temperature environment is appropriately prevented, and the heat resistance of the aromatic polysulfone composition is also improved. When the reduced viscosity of the polyethersulfone is not more than the above upper limit value, the handling and moldability of the aromatic polysulfone composition can be improved.

The reduced viscosity of the polyether sulfone can be measured by the following method.
The viscosity (η) of 1 dL of a solution prepared by dissolving 1 g of polyether sulfone in N, N-dimethylformamide is measured at 25 ° C. using an Ostwald-type viscosity tube.
Further, the viscosity (η0) of N, N-dimethylformamide, which is a solvent, is measured at 25 ° C. using an Ostwald type viscosity tube.
The specific viscosity ratio ((η-η0) / η0) is obtained from the viscosity (η) of the solution and the viscosity (η0) of the solvent. The reduced viscosity (dL / g) is determined by dividing this specific viscosity by the concentration of the solution (about 1 g / dL).

The ratio of the content of polyether sulfone in the thermoplastic resin composition is preferably 40% by mass or more and 100% by mass or less, more preferably 45% by mass or more and 100% by mass or less, based on 100% by mass of the thermoplastic resin composition. It is preferable that 50% by mass or more and 100% by mass or less is more preferable, and 60% by mass or more and 100% by mass or less is particularly preferable.

-Inorganic filler The inorganic filler contained in the thermoplastic resin composition is not limited as long as it forms an injection molded product. A fibrous filler is preferable because it can impart strength and rigidity suitable for a vehicle suspension member.

Examples of fibrous inorganic fillers include glass fibers; carbon fibers such as PAN-based, pitch-based, rayon-based, phenol-based, and lignin-based carbon fibers; ceramic fibers such as silica fibers, alumina fibers, and silica-alumina fibers; and iron. , Gold, copper, aluminum, brass, stainless steel and other metal fibers, silicon carbide fibers, boron fibers and the like. Further, whiskers such as potassium titanate whiskers, barium titanate whiskers, wollast night whiskers, aluminum borate whiskers, silicon nitride whiskers, and silicon carbide whiskers can also be mentioned. Among these, carbon fiber or glass fiber is preferable, and carbon fiber is more preferable.

Among them, PAN-based carbon fibers are preferably used because they have a good balance of tensile strength, tensile elastic modulus, and tensile elongation, and can leave a long residual fiber length.

Examples of the PAN-based carbon fiber include "Treca (registered trademark)" manufactured by Toray Industries, Inc., "Pyrofil (registered trademark)" manufactured by Mitsubishi Chemical Corporation, and "Tenax (registered trademark)" manufactured by Teijin Limited.

Examples of pitch-based carbon fibers include "Dialed (registered trademark)" manufactured by Mitsubishi Chemical Corporation, "GRANOC (registered trademark)" manufactured by Nippon Graphite Fiber Co., Ltd., and "Donna Carbo (registered trademark)" manufactured by Osaka Gas Chemical Corporation. , "Kureka (registered trademark)" manufactured by Kureha Corporation.

Glass fibers include E glass (ie, non-alkali glass), S glass or T glass (ie, high strength, high elasticity glass), C glass (ie, glass for acid resistant applications), D glass (ie, low dielectric constant). Glass fibers for FRP tempering materials such as ECR glass (ie, _{E-glass substitute glass that does not contain B 2} O ₃ , F ₂ ), AR glass (ie, glass for alkali-resistant applications). Among them, E glass is preferably used because of its balance of strength and elastic modulus and its availability.

The content of the fibrous filler in the thermoplastic resin composition is preferably 1 part by mass or more and 120 parts by mass or less, more preferably 1 part by mass or more and 115 parts by mass or less, with respect to 100 parts by mass of the thermoplastic resin. More than parts and less than 115 parts by mass are more preferable, and more than 20 parts by mass and less than 110 parts by mass are particularly preferable.

The content of the fibrous filler in the thermoplastic resin composition is preferably 0% by mass or more and 60% by mass or less, more preferably 1% by mass or more and 55% by mass or less, based on 100% by mass of the thermoplastic resin composition. It is more preferably 10% by mass or more and 55% by mass or less, and particularly preferably 20% by mass or more and 50% by mass or less.

-Other components The thermoplastic resin composition may contain one or more other components such as fillers and additives, if necessary, in addition to the above-mentioned thermoplastic resin and inorganic filler as raw materials.

The filler may be a plate-shaped filler, a spherical filler or other granular filler. Further, the filler may be an inorganic filler or an organic filler.

Examples of plate-like inorganic fillers include talc, mica, graphite, wollastonite, glass flakes, barium sulfate and calcium carbonate. The mica may be muscovite, phlogopite, fluorine phlogopite, or tetrasilicon mica.

Examples of granular inorganic fillers include silica, alumina, titanium oxide, glass beads, glass balloons, boron nitride, silicon carbide, and calcium carbonate.

Examples of additives include flame retardants, conductivity-imparting agents, crystal nucleating agents, UV absorbers, antioxidants, anti-vibration agents, antibacterial agents, insect repellents, deodorants, anti-coloring agents, heat stabilizers, and release agents. Examples include molds, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, antifoaming agents, viscosity modifiers and surfactants.

The vehicle suspension member of the present embodiment has the following aspects.

"1" A vehicle suspension member including an injection molded product made of a thermoplastic resin composition.
The vehicle suspension member has an arm portion provided with bolt holes for connecting to other parts.
A vehicle suspension member having an arm portion having a thickness of less than 20 mm.

"2" The vehicle suspension member according to "1", wherein the thickness of the arm portion is preferably 18 mm or less, more preferably 16 mm or less, and further preferably 15 mm or less.

"3" The vehicle suspension member according to "1" or "2", wherein the thickness of the arm portion is preferably 5 mm or more, more preferably 6 mm or more, and preferably 7 mm or more.
"4" The vehicle suspension member according to any one of "1" to "3", wherein the vehicle suspension member has a main body portion provided with a central hole and the arm portion.
"5" The vehicle suspension member according to "4", wherein a gate mark continuous on the entire circumference in the circumferential direction is provided on the inner peripheral surface of the central hole.
"6" The vehicle suspension member according to "4" or "5", wherein the arm portion and the main body portion are integrally molded by injection molding the thermoplastic resin composition.

"7" The vehicle suspension member according to any one of "1" to "6", wherein the thermoplastic resin composition contains a liquid crystal polyester or a polyether sulfone.
"8" The vehicle suspension member according to any one of "1" to "7", wherein the thermoplastic resin composition contains an inorganic filler.
"9" The vehicle suspension member according to "8", wherein the inorganic filler is a fibrous filler.
"10" The vehicle suspension member according to "9", wherein the fibrous filler is preferably carbon fiber, more preferably PAN-based carbon fiber.

"11" The vehicle suspension member according to any one of "1" to "10", wherein the vehicle suspension member is an upright having a central hole for receiving a wheel bearing.
"12" The vehicle suspension member according to any one of "1" to "11", wherein the upright further has a lower arm connecting portion and an upper arm connecting portion.

"13" The vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, and preferably, of the thickness of the plurality of arm portions, at least one of the arm portions. The thickness is 5 mm or more and less than 20 mm, more preferably the thickness of at least two arm portions is 5 mm or more and less than 20 mm, and further preferably the thickness of all the arm portions is 5 mm or more and less than 20 mm. The vehicle suspension member according to any one of "1" to "12".

"14" The vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, preferably the thickness of at least one of the plurality of arm portions. The thickness is 6 mm or more and 18 mm or less, more preferably the thickness of at least two arm portions is 6 mm or more and 18 mm or less, and further preferably the thickness of all the arm portions is 6 mm or more and 18 mm or less. The vehicle suspension member according to any one of "1" to "13".

The "15" vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, preferably the thickness of at least one of the plurality of arm portions. The thickness is 7 mm or more and 16 mm or less, more preferably the thickness of at least two arm portions is 7 mm or more and 16 mm or less, and further preferably the thickness of all the arm portions is 7 mm or more and 16 mm or less. The vehicle suspension member according to any one of "1" to "14".

The "16" vehicle suspension member has a plurality of arm portions provided with bolt holes for connecting to other parts, preferably the thickness of at least one of the plurality of arm portions. The thickness is 7 mm or more and 15 mm or less, more preferably the thickness of at least two arm portions is 7 mm or more and 15 mm or less, and further preferably the thickness of all the arm portions is 7 mm or more and 15 mm or less. The vehicle suspension member according to any one of "1" to "15".

<Manufacturing method of suspension members for vehicles>
Vehicle suspension members such as the front upright of the first embodiment, the knuckle of the second embodiment, and the suspension arm of the third embodiment shall be manufactured by a known injection molding method using the thermoplastic resin composition. Can be done. That is, using the above-mentioned thermoplastic resin composition as a molding material, a known injection molding machine is used to melt the thermoplastic resin composition, and the melted thermoplastic resin composition is used as a gold in the shape of a vehicle suspension member. It is filled in a mold and injection molded. The mold in the shape of the suspension member for a vehicle may be provided with a metal nut having the shape of a bolt hole for connecting to other parts in advance.

In a vehicle suspension member having an arm portion provided with bolt holes for connecting to other parts, the arm portion provided with bolt holes is most likely to be deformed during injection molding. According to the results of the simulation described later, in the front upright 10, the tips of the upper arm portions 32, 33 for connecting to the brake caliper out of the four arm portions 30, 31, 32, 33. The amount of contraction (that is, the amount of deformation) of the part is the largest. In the vehicle suspension member of the present embodiment, the thickness of the arm portion provided with the bolt hole for connecting to other parts is less than 20 mm, so that the arm portion provided with the bolt hole during injection molding is deformed. The amount can be reduced, and the dimensional accuracy of the bolt hole position can be improved.

When injection molding a vehicle suspension member having an arm portion provided with bolt holes for connecting to other parts, a resin confluence, that is, a weld is generated around the bolt holes, and the bolt holes are formed. There is a risk that the strength of the provided arm portion will decrease. In order to maintain sufficient strength and rigidity of the arm portion provided with bolt holes for connecting to other parts, the thickness of the arm portion provided with bolt holes is preferably 5 mm or more, preferably 6 mm or more. More preferably, it is more preferably 7 mm or more.

In the method for manufacturing a vehicle suspension member having a central hole 40, such as the front upright 10 of the first to fourth embodiments, injection using a disc gate provided over the entire inner peripheral surface of the central hole 40 is used. The molding method is preferable. According to the results of the simulation described later, a method of adopting an injection molding method using a disc gate from the inner circumference of the central hole of the vehicle suspension member is adopted rather than an injection molding method in which a gate position is provided at the end of the vehicle suspension member. However, the amount of deformation of the arm portion provided with the bolt holes for connecting to other parts can be reduced. By providing a continuous gate position on the inner peripheral surface of the central hole and adopting an injection molding method using a disc gate, the amount of deformation of the arm portion provided with the bolt hole is reduced. It is possible to improve the dimensional accuracy of the bolt hole position.

Here, when the thermoplastic resin composition is charged into the injection molding machine, each component (neat pellet of thermoplastic resin, fiber filler, etc.) may be separately charged into the injection molding machine, or a part or a part thereof may be charged in advance. All the components may be mixed and charged into an injection molding machine as a mixture.
Examples of known injection molding machines include J450EIII manufactured by Japan Steel Works, Ltd., TR450EH3 manufactured by Sodick Co., Ltd., and PS40E5ASE type hydraulic horizontal molding machine manufactured by Nissei Resin Industry Co., Ltd.

The temperature condition of injection molding is appropriately determined according to the type of the thermoplastic resin composition, and the cylinder temperature of the injection molding machine is set to a temperature 10 to 80 ° C. higher than the flow start temperature of the thermoplastic resin composition to be used. Is preferable.
For example, when the thermoplastic resin composition contains a liquid crystal polyester, the melt-kneading temperature (plasticized portion) is preferably 250 to 370 ° C, more preferably 260 to 360 ° C, still more preferably 270 to 350 ° C.
The temperature of the measuring unit or the plunger unit is preferably 280 to 400 ° C, more preferably 290 to 380 ° C, and even more preferably 300 to 370 ° C.

The temperature of the mold is preferably set in the range of room temperature (for example, 23 ° C.) to 180 ° C. from the viewpoint of the cooling rate and productivity of the thermoplastic resin composition.
As other injection conditions, the screw rotation speed, back pressure, injection speed, holding pressure, holding time, etc. may be appropriately adjusted.

The vehicle suspension member of each embodiment described above has an arm portion provided with bolt holes for connecting to other components, and the thickness of the arm portion is less than 20 mm, so that the dimensional accuracy is correct. In particular, the dimensional accuracy of the bolt hole position is excellent.

The method for manufacturing a vehicle suspension member of the present embodiment has the following aspects.

"17" The item according to any one of "1" to "16", which comprises melting the thermoplastic resin composition, filling the molten thermoplastic resin composition in a mold, and injection molding. The method for manufacturing a vehicle suspension member according to the description.
"18" The vehicle suspension member has a central hole, and the molten thermoplastic resin composition is filled into a mold and injected from a disc gate provided over the entire inner peripheral surface of the central hole. The method for manufacturing a suspension member for a vehicle according to the above "17", which includes molding.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the examples shown below.

<Simulation of plastic injection molding>
[Reference example 1]
When simulating the injection molding of the front upright of the first embodiment shown in FIGS. 1 and 2 using the plastic injection molding simulation software (Moldflow Insight 2016, manufactured by Autodesk Inc.) under the following conditions. The amount of shrinkage from the position of the mold, that is, the amount of deformation was evaluated. The volume of the front upright is 833 cm ³ , and the projected area is 386 cm ² . In Reference Example 1, a disc gate having a diameter of 67 mm and a disc portion thickness of 5 mm is used by providing a continuous gate position on the inner peripheral surface of the central hole 40 over the entire circumference in the circumferential direction. The thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper is 13 mm.

Molding material: Pellets of thermoplastic resin composition consisting of 30% by mass of glass fiber and 70% by mass of liquid crystal polyester (Sumitomo Chemical Co., Ltd., Sumika Super (registered trademark) LCP, E6006L)
Resin temperature: 360 ° C
Mold temperature: 120 ° C
Injection time: 5 seconds Cooling time: 50 seconds Holding pressure: 100 MPa

More specifically, it was evaluated how much the position of each point in the front view of the upright shown in FIG. 1 contracts from the position of the mold starting from the center of the central hole 40. Of the four arm portions 30, 31, 32, 33, the amount of contraction (that is, the amount of deformation) at the tip of the upper two arm portions 32, 33 for connecting to the brake caliper is the largest. The maximum amount of deformation was 0.711 mm. The amount of contraction (that is, the amount of deformation) at the tips of the lower two arm portions 30 and 31 was 0.511 mm.

[Reference example 2]
Similar to Reference Example 1, each point in the front view of the upright shown in FIG. 1 except that the thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper was changed to 5 mm. It was evaluated how much the position contracted from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 0.702 mm. The amount of contraction (that is, the amount of deformation) at the tips of the lower two arm portions 30 and 31 was 0.512 mm.

[Reference example 3]
Similar to Reference Example 1, each point in the front view of the upright shown in FIG. 1 except that the thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper was changed to 8 mm. It was evaluated how much the position contracted from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 0.704 mm. The amount of contraction (that is, the amount of deformation) at the tips of the lower two arm portions 30 and 31 was 0.516 mm.

[Reference example 4]
Similar to Reference Example 1, each point in the front view of the upright shown in FIG. 1 except that the thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper was changed to 20 mm. It was evaluated how much the position contracted from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 0.749 mm. The amount of contraction (that is, the amount of deformation) at the tips of the lower two arm portions 30 and 31 was 0.547 mm.

[Reference Example 5]
Similar to Reference Example 1, each point in the front view of the upright shown in FIG. 1 except that the thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper was changed to 30 mm. It was evaluated how much the position contracted from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 0.766 mm. The amount of contraction (that is, the amount of deformation) at the tips of the lower two arm portions 30 and 31 was 0.604 mm.

The results of the maximum deformation amount of the simulations of Reference Examples 1 to 5 are shown in FIG. Reference Examples 1 to 5 use a thermoplastic resin composition containing glass fiber and liquid crystal polyester as a molding material. As the thickness of the arm portion increases, the maximum amount of deformation at the tip of the arm portion increases. In particular, the amount of deformation after injection molding increases sharply at a thickness of 13 mm to 20 mm. This is because in Reference Examples 4 to 5 in which the thickness of the arm portion is 20 to 30 mm, the region having a large volume shrinkage ratio rapidly increases inside the arm portion, and the core with weak fiber orientation (that is, low mechanical properties). Since the number of layers increases, it is considered that the arm portion having a thickness of 20 to 30 mm cannot withstand the volumetric contraction load and the amount of deformation increases.

The above simulation is carried out using a thermoplastic resin composition containing glass fiber and liquid crystal polyester as a molding material. If the fiber type is different, the absolute value of the dimensional change changes because the fiber characteristics are different, but the fiber orientation during molding does not affect the dimensional change. Therefore, the relationship between the maximum change amount of the tip of the arm part with respect to the thickness of the arm part is that the glass fiber is changed to an inorganic filler such as carbon fiber, the type of the inorganic filler is different, or the thermoplastic resin. It is considered that the same tendency is considered even if the composition of the composition is different.

For example, even when a thermoplastic resin composition containing carbon fibers and liquid crystal polyester is used as a molding material, the maximum amount of deformation at the tip of the arm portion decreases as the thickness of the arm portion decreases, and in particular, the thickness is 20 mm to 13 mm. It is considered that the amount of deformation after injection molding decreases sharply.

[Reference example 6]
Similar to Reference Example 1, the position of each point in the front view of the upright shown in FIG. 1 is the center of the center hole 40, except that the injection molding conditions of Reference Example 1 are changed to the following conditions. As a starting point, how much shrinkage from the position of the mold, that is, the amount of deformation was evaluated. The thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper is 13 mm.

Molding material: Thermoplastic resin composition consisting of 30% by mass of glass fiber and 70% by mass of polyether sulfone (PES) (Sumitomo Chemical Co., Ltd., Sumika Excel (registered trademark) PES, 4101GL30)
Resin temperature: 360 ° C
Mold temperature: 120 ° C
Injection time: 5 seconds Cooling time: 50 seconds Holding pressure: 100 MPa

As a result, as in Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 1.199 mm.

[Reference Example 7]
Similar to Reference Example 6, each point in the front view of the upright shown in FIG. 1 except that the thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper was changed to 5 mm. It was evaluated how much the position contracted from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 6, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 1.126 mm.

[Reference Example 8]
Similar to Reference Example 1, each point in the front view of the upright shown in FIG. 1 except that the thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper was changed to 8 mm. It was evaluated how much the position contracted from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 1.185 mm.

[Reference example 9]
Similar to Reference Example 1, each point in the front view of the upright shown in FIG. 1 except that the thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper was changed to 20 mm. It was evaluated how much the position contracted from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 1.250 mm.

[Reference Example 10]
Similar to Reference Example 1, each point in the front view of the upright shown in FIG. 1 except that the thickness of the arm portions 30, 31, 32, 33 for connecting to the brake caliper was changed to 30 mm. It was evaluated how much the position contracted from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 1.281 mm.

The result of the maximum deformation amount of the simulation of Reference Examples 6 to 10 is shown in FIG. Reference Examples 6 to 10 use a thermoplastic resin composition containing glass fiber and polyether sulfone (PES) as a molding material. Similar to the result of the maximum deformation amount of the simulations of Reference Examples 1 to 5 (FIG. 9), the maximum deformation amount of the tip of the arm portion increases as the thickness of the arm portion increases. In particular, the amount of deformation after injection molding increases sharply at a thickness of 13 mm to 20 mm. This is because in Reference Examples 9 to 10 in which the thickness of the arm portion is 20 to 30 mm, the region having a large volume shrinkage ratio rapidly increases inside the arm portion, and the core with weak fiber orientation (that is, low mechanical properties). Since the number of layers increases, it is considered that the arm portion having a thickness of 20 to 30 mm cannot withstand the volumetric contraction load and the amount of deformation increases.

The above simulation is carried out using a thermoplastic resin composition containing glass fiber and a thermoplastic resin as a molding material. If the fiber type is different, the absolute value of the dimensional change changes because the fiber characteristics are different, but the fiber orientation during molding does not affect the dimensional change. Therefore, the relationship between the maximum change amount of the tip of the arm part with respect to the thickness of the arm part is that the glass fiber is changed to an inorganic filler such as carbon fiber, the type of the inorganic filler is different, or the thermoplastic resin. It is considered that the same tendency is considered even if the composition of the composition is different.

For example, even when a thermoplastic resin composition containing carbon fibers is used as a molding material, the maximum amount of deformation at the tip of the arm portion decreases as the thickness of the arm portion decreases, and injection molding is particularly performed at a thickness of 20 mm to 13 mm. It is considered that the amount of later deformation decreases sharply.

Further, the one using the thermoplastic resin composition containing the glass fibers and liquid crystal polyester of Reference Examples 1 to 5 as a molding material (FIG. 9) is the heat containing the glass fibers and polyether sulfone (PES) of Reference Examples 6 to 10. Compared with the case where the plastic resin composition is used as the molding material (FIG. 10), the effect of suppressing the shrinkage change of the arm portion by reducing the thickness of the arm portion is more remarkable.

An arm made of a thermoplastic resin composition containing a liquid crystal polyester as a molding material has a thinner arm than a molding material of a thermoplastic resin composition containing a polyether sulfone (PES). It is considered that the effect of suppressing the contraction change of the part is excellent.

[Reference Example 11]
The front upright of the first embodiment shown in FIGS. 1 and 2 is shown in FIG. 1 in the same manner as in Reference Example 1 except that the front upright of the first embodiment is changed to use a direct gate from the center of the tip of the lower arm connecting portion 50. It was evaluated how much the position of each point in the front view of the upright shrinks from the position of the mold with the center of the central hole 40 as the starting point. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 0.868 mm. Further, the ratio of the maximum deformation amount of Reference Example 1 in which the gate positions continuous to the entire circumference in the circumferential direction were provided on the inner peripheral surface of the central hole to 0.711 mm was 1.222.

[Reference Example 12]
The front upright of the first embodiment shown in FIGS. 1 and 2 is shown in FIG. 1 in the same manner as in Reference Example 1 except that the front upright of the first embodiment is changed to use a direct gate from the center of the tip of the upper arm connecting portion 60. It was evaluated how much the position of each point in the front view of the upright shown contracts from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 1, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 0.909 mm. Further, the ratio of the maximum deformation amount of Reference Example 1 in which the gate positions continuous to the entire circumference in the circumferential direction were provided on the inner peripheral surface of the central hole to 0.711 mm was 1.279.

[Reference Example 13]
The front upright of the first embodiment shown in FIGS. 1 and 2 is shown in FIG. 1 in the same manner as in Reference Example 6 except that the front upright of the first embodiment is changed to use a direct gate from the center of the tip of the lower arm connecting portion 50. It was evaluated how much the position of each point in the front view of the upright shrinks from the position of the mold with the center of the central hole 40 as the starting point. Similar to Reference Example 6, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 1.222 mm. Further, the ratio of the maximum deformation amount of Reference Example 6 in which the gate positions continuous to the entire circumference in the circumferential direction were provided on the inner peripheral surface of the central hole with respect to 1.199 mm was 1.019.

[Reference Example 14]
The front upright of the first embodiment shown in FIGS. 1 and 2 is shown in FIG. 1 in the same manner as in Reference Example 6 except that the front upright of the first embodiment is changed to use a direct gate from the center of the tip of the upper arm connecting portion 60. It was evaluated how much the position of each point in the front view of the upright shown contracts from the position of the mold starting from the center of the central hole 40. Similar to Reference Example 6, the amount of contraction (that is, the amount of deformation) at the tips of the two arm portions 32 and 33 was the largest, and the maximum amount of deformation was 1.223 mm. Further, the ratio of the maximum deformation amount of Reference Example 6 in which the gate positions continuous to the entire circumference in the circumferential direction were provided on the inner peripheral surface of the central hole with respect to 1.199 mm was 1.020.

The results of the maximum deformation amount of the simulations of Reference Examples 1, 6 and 11 to 14 are shown in FIG. Similarly, from the simulation results of Reference Example 1, Reference Example 6, and Reference Examples 11 to 14, the maximum of Reference Example 6 in which a continuous gate position is provided on the inner peripheral surface of the central hole in the entire circumferential direction. The ratio of each maximum deformation amount to the deformation amount is shown in FIG.

In FIGS. 11 and 12, an upright having a continuous gate position on the inner peripheral surface of the central hole in the circumferential direction is provided at the end of the lower arm connecting portion and the gate position at the end of the upper arm connecting portion. It is shown that the amount of shrinkage (that is, the amount of deformation) after injection molding is smaller than that of the upright provided with. Further, FIGS. 11 and 12 show a thermoplastic resin composition made of glass fiber and liquid crystal polyester rather than an upright made of a thermoplastic resin composition (4101GL30) made of glass fiber and polyether sulfone (PES) as a molding material. It is shown that the upright using (E6006L) as a molding material has a more remarkable influence on the shrinkage amount (that is, the deformation amount) after injection molding by the gate position.

The above simulation is also carried out using a thermoplastic resin composition containing glass fiber and a thermoplastic resin as a molding material. If the fiber type is different, the absolute value of the dimensional change changes because the fiber characteristics are different, but it does not affect the fiber orientation during molding. Therefore, the relationship of the maximum change amount of the tip of the arm portion with respect to the gate position is that the glass fiber is changed to an inorganic filler such as carbon fiber, the type of the inorganic filler is different, or the thermoplastic resin composition. It is considered that the same tendency is considered even if the composition is different.

For example, even when a thermoplastic resin composition containing carbon fibers is used as a molding material, an upright having a continuous gate position on the inner peripheral surface of the central hole is provided at the end of the lower arm connecting portion. It is also considered that the amount of shrinkage (that is, the amount of deformation) after injection molding is smaller than that of an upright having a gate position at the end of the upper arm connection portion.

<Bending test of plastic molding material>
[Reference Example 15]
Pellets of a thermoplastic resin composition consisting of 30% by mass of glass fiber and 70% by mass of liquid crystal polyester (manufactured by Sumitomo Chemical Co., Ltd., Sumika Super (registered trademark) LCP, E6006L) were used in an injection molding machine TR450EH3 (manufactured by Sodick Co., Ltd.). ) Was melt-kneaded at 360 ° C. and injection molded into a mold at a mold temperature of 100 ° C. under the following conditions to form a dumbbell-shaped test piece (1A) (thickness 4 mm) conforming to ISO527. ..

-Injection molding conditions Injection speed: 100 mm / s
Screw rotation speed: 100 rpm
Holding pressure: 100 MPa
Holding time: 5 seconds Back pressure: 1 MPa

(Bending test)
From the obtained dumbbell-shaped test piece, cutting was performed so as to have a width of 10 mm × a length of 80 mm and a shape without a notch, and five plate-shaped test pieces were obtained. Using the obtained five plate-shaped test pieces, a bending test was performed under the following measurement conditions, and the maximum bending load was measured 5 times. For the maximum bending load of the plate-shaped test piece, the average value of the obtained measured values was adopted. The results are shown in Table 1.
-Measuring conditions Measuring device: Tencilon RTG-1250
Test type: 3-point bending test Test speed: 2 mm / min
Distance between fulcrums: 64 mm

[Reference Example 16]
A dumbbell-shaped test piece was formed in the same manner as in Reference Example 15 except that the thickness of the dumbbell-shaped test piece was changed to 2 mm, and five plate-shaped test pieces were obtained.
Using the obtained five plate-shaped test pieces, the maximum bending load was measured five times in the same manner as in Reference Example 15, and the maximum bending load of the plate-shaped test piece was determined. The results are shown in Table 1.

[Reference example 17]
The dumbbell-shaped test piece was molded in the same manner as in Reference Example 15 except that the thickness of the dumbbell-shaped test piece was changed to 8 mm, and five plate-shaped test pieces were obtained.
Using the obtained five plate-shaped test pieces, the maximum bending load was measured five times in the same manner as in Reference Example 15, and the maximum bending load of the plate-shaped test piece was determined. The results are shown in Table 1.

[Reference Example 18]
The molding material was changed to pellets of a thermoplastic resin composition consisting of 30% by mass of glass fiber and 70% by mass of polyether sulfone (PES) (Sumika Excel (registered trademark) PES, 4101GL30 manufactured by Sumitomo Chemical Co., Ltd.). Except for this, in the same manner as in Reference Example 15, melt-kneading is performed at 360 ° C. using an injection molding machine TR450EH3 (manufactured by Sodick Co., Ltd.), and injection molding is performed into a mold having a mold temperature of 100 ° C. under the following conditions. A dumbbell-shaped test piece (1A) (thickness 4 mm) conforming to ISO527 was formed by the above method.

-Injection molding conditions Injection speed: 100 mm / s
Screw rotation speed: 100 rpm
Holding pressure: 100 MPa
Holding time: 5 seconds Back pressure: 1 MPa

(Bending test)
From the obtained dumbbell-shaped test pieces, five plate-shaped test pieces were obtained in the same manner as in Reference Example 15.
Using the obtained five plate-shaped test pieces, the maximum bending load was measured five times in the same manner as in Reference Example 15, and the maximum bending load of the plate-shaped test piece was determined. The results are shown in Table 1.

[Reference Example 19]
The dumbbell-shaped test piece was molded in the same manner as in Reference Example 18 except that the thickness of the dumbbell-shaped test piece was changed to 2 mm, and five plate-shaped test pieces were obtained.
Using the obtained five plate-shaped test pieces, the maximum bending load was measured five times in the same manner as in Reference Example 15, and the maximum bending load of the plate-shaped test piece was determined. The results are shown in Table 1.

[Reference Example 20]
The dumbbell-shaped test piece was molded in the same manner as in Reference Example 18 except that the thickness of the dumbbell-shaped test piece was changed to 8 mm, and five plate-shaped test pieces were obtained.
Using the obtained five plate-shaped test pieces, the maximum bending load was measured five times in the same manner as in Reference Example 15, and the maximum bending load of the plate-shaped test piece was determined. The results are shown in Table 1.

From the results in Table 1, even when the thermoplastic resin composition (E6006L) composed of glass fiber and liquid crystal polyester is used as the molding material, the thermoplastic resin composition (4101GL30) composed of glass fiber and polyether sulfone (PES) is molded. Even when the material is used, the thickness of the injection-molded product is preferably 5 mm or more, more preferably 6 mm or more, still more preferably 7 mm or more, because the strength and rigidity of the test piece can be ensured. it is conceivable that.

<< Molding of front upright >>
(Measuring method of flow start temperature of powdered liquid crystal polyester and pellets)
Using a flow tester (“CFT-500 type” manufactured by Shimadzu Corporation), about 2 g of liquid crystal polyester or pellets, which will be described later, was filled into a cylinder equipped with a die having a nozzle having an inner diameter of 1 mm and a length of 10 mm. Next, the liquid crystal polyester was melted and extruded from a nozzle while raising the temperature at a temperature rising rate of 4 ° C./min under a load of 9.8 MPa (100 kg / cm ^{2) to obtain a viscosity of 4800 Pa · s (48,000 poisons).} The indicated temperature was measured and used as the flow start temperature of the liquid crystal polyester or pellets.

<Manufacturing of liquid crystal polyester>
A reactor equipped with a stirrer, torque meter, nitrogen gas introduction tube, thermometer and reflux cooler, 6-hydroxy-2-naphthoic acid (1034.99 g, 5.5 mol) and 2,6-naphthalenedicarboxylic acid. Total of acid (378.33 g, 1.75 mol), terephthalic acid (83.07 g, 0.5 mol), hydroquinone (272.52 g, 2.475 mol, 2,6-naphthalenedicarboxylic acid and terephthalic acid) 0.225 mol excess with respect to the amount), anhydrous acetic acid (1226.87 g, 12 mol) and 1-methylimidazole (0.17 g) as a catalyst were added, and the gas in the reactor was replaced with nitrogen gas. .. Then, the temperature was raised from room temperature to 145 ° C. over 15 minutes with stirring under a nitrogen gas stream, and the mixture was refluxed at 145 ° C. for 1 hour.

Then, while distilling off by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 145 ° C. to 310 ° C. over 3.5 hours and maintained at 310 ° C. for 3 hours. Then, the contents were taken out and cooled to room temperature to obtain a solid matter. The obtained solid material was pulverized with a pulverizer to a particle size of about 0.1 to 1 mm. Then, in a nitrogen atmosphere, the temperature was raised from room temperature to 250 ° C. over 1 hour, the temperature was raised from 250 ° C. to 310 ° C. over 10 hours, and the temperature was maintained at 310 ° C. for 5 hours to carry out solid phase polymerization. After solid-phase polymerization, it was cooled to obtain a powdery liquid crystal polyester.

The obtained liquid crystal polyester contains 55 mol% of the repeating unit (1) in which ^{Ar 1} in the above formula (1) is a 2,6-naphthylene group with respect to the total amount of all the repeating units, and the above formula (2). ), The ^{repeating unit (2) in which Ar 2} is a 2,6-naphthylene group is 17.5 mol%, the repeating unit (2) in which Ar ² is a 1,4-phenylene group is 5 mol%, and the above formula. Ar ^{3 in} (3) had 22.5 mol% of the repeating unit (3) which was a 1,4-phenylene group, and its flow start temperature was 322 ° C.

<Manufacturing of pellets>
After blending 70% by mass of the obtained powdered liquid crystal polyester and 30% by mass of PAN-based carbon fiber (carbon fiber roving "TR50S15LAD" manufactured by Mitsubishi Chemical cut to a length of 3 mm), a twin-screw extruder ("TEM-41SS" manufactured by Toshiba Machine Co., Ltd.) was granulated at a cylinder temperature of 330 ° C. to obtain pellets of a thermoplastic resin composition composed of 30% by mass of PAN-based carbon fibers and 70% by mass of liquid crystal polyester. The flow start temperature of the pellets thus obtained was 306 ° C.

[Example 1]
Using the obtained pellets as a molding material, the front upright 10 shown in FIGS. 1 and 2 was injection molded under the following conditions. In the first embodiment, a gate position continuous with the entire circumference in the circumferential direction is provided on the inner peripheral surface of the central hole 40, and injection molding is performed using a disc gate having a diameter of 67 mm and a disc portion having a thickness of 5 mm. The volume of the front upright is 833 cm ³ , and the projected area is 386 cm ² . The thickness of the arm portion 30 for connecting to the brake caliper was 13 mm. The thickness of the arm portions 31, 32, 33 for connecting to the brake caliper was also 13 mm. The thickness of each arm was measured using a caliper. The dimensional change from the mold dimensions was small, and it was possible to mold a front upright with the target dimensional accuracy.

Molding material: Pellet injection molding machine for thermoplastic resin composition consisting of 30% by mass of PAN-based carbon fiber and 70% by mass of liquid crystal polyester: J450EIII (manufactured by Japan Steel Works, Ltd.)
Resin temperature: 360 ° C
Mold temperature: 120 ° C
Injection time: 5 seconds Cooling time: 50 seconds Holding pressure: 100 MPa

(Strength test)
The obtained front upright 10 of Example 1 was subjected to a strength test using a material testing machine (manufactured by Shimadzu Corporation, Autograph (registered trademark) AG-5000D).

Specifically, as shown in FIG. 13, the front upright 10 of the first embodiment is fixed to the base plate 5 by using the jig 1, the jig 2, and the bolt 6, and the end portion of the lower arm connecting portion 50 is fixed. The jig 3 connected to the jig 4 was pulled upward by the material tester under the following tensile conditions, and the load on the movement amount (that is, the stroke) of the head of the material tester was recorded. .. The load (that is, test force) when the front upright cracked was 6.64 kN.

-Tensile conditions Test mode: Single Test type: Tensile test speed: 2 mm / min
Load cell: 50kN

[Example 2]
The molding material is made into pellets of a thermoplastic resin composition (manufactured by Sumitomo Chemical Co., Ltd., Sumiproi (registered trademark) S series, CS5600) composed of 30% by mass of PAN-based carbon fiber and 70% by mass of polyether sulfone (PES). The front upright 10 shown in FIGS. 1 and 2 was injection-molded in the same manner as in Example 1 except that the changes were made.

The thickness of the arm portion 30 for connecting to the brake caliper was 13 mm. The thickness of the arm portions 31, 32, 33 for connecting to the brake caliper was also 13 mm. The thickness of each arm was measured using a caliper. The dimensional change from the mold dimensions was small, and it was possible to mold a front upright with the target dimensional accuracy.

The obtained front upright of Example 2 was subjected to a strength test in the same manner as in Example 1. The load (that is, test force) when the front upright cracked was 5.66 kN.

Uprights that use a thermoplastic resin composition made of PAN-based carbon fiber and liquid crystal polyester as a molding material are more like uprights that use a thermoplastic resin composition made of PAN-based carbon fiber and polyether sulfone (PES) as a molding material. Showed higher test power than.

10 ... Upright (suspension member for vehicles), 11, 12, 13 ... Knuckle (suspension member for vehicles), 20, 21, 22, 23 ... Bolt holes for connection with brake calipers (others) Bolt holes for connection with parts), 30, 31, 32, 33 ... Arm part, 30d ... Arm part thickness, 40 ... Center hole, 45 ... Main body part, 50 ...・ Lower arm connection part, 51, 52 ・ ・ ・ Lower arm, 60 ・ ・ ・ Upper arm connection part, 61, 62 ・ ・ ・ Upper arm, 70 ・ ・ ・ Brake caliper 1,2,3,4 ・ ・ ・ Jig, 5 ... Base plate, 6 ... Bolt

Claims (8)

A vehicle suspension member including an injection molded product made of a thermoplastic resin composition.
The vehicle suspension member has an arm portion provided with bolt holes for connecting to other parts.
A vehicle suspension member having an arm portion having a thickness of less than 20 mm. The vehicle suspension member according to claim 1, wherein the thickness of the arm portion is 5 mm or more. The vehicle suspension member according to claim 1 or 2, wherein the thermoplastic resin composition contains a liquid crystal polyester. The vehicle suspension member according to any one of claims 1 to 3, wherein the vehicle suspension member is an upright having a central hole for receiving a wheel bearing. The vehicle suspension member according to claim 4, wherein a gate mark continuous on the entire circumference in the circumferential direction is provided on the inner peripheral surface of the central hole. The vehicle suspension member according to any one of claims 1 to 5, wherein the thermoplastic resin composition contains an inorganic filler. The vehicle suspension member according to claim 6, wherein the inorganic filler is a fibrous filler. The vehicle suspension member according to claim 7, wherein the fibrous filler is carbon fiber.

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