JP4895771B2 - Attenuator structure - Google Patents

Description

  The present invention relates to a damping part structure, and more particularly to an improvement of a damping part structure suitable for implementation in a piston part in a cylinder body in a hydraulic shock absorber.

  There have been various proposals for a damping part structure suitable for realizing a piston part in a cylinder body in a hydraulic shock absorber. Basically, there is a port as a flow path opened in a piston body as a valve seat member. It is supposed that it has an annular leaf valve that closes its downstream end so as to be openable and closable by an outer peripheral side bending portion.

  And in said damping | damping part structure, the annular leaf valve has obstruct | occluded the port when the outer peripheral side bending part is pressed on the piston body by the urging | biasing force from the coil spring arrange | positioned on the back side. However, when there is a hydraulic action through the port that overcomes the urging force of the coil spring, the outer side bending portion is bent to appear between the piston body and this gap is made to act as hydraulic oil. Passes through and generates a predetermined damping force.

  On the other hand, for example, as disclosed in Patent Document 1, in an attenuation part structure embodied in a recent piston part, the annular leaf valve is annular while the outer diameter is smaller than the outer diameter of the annular leaf valve. It is assumed that a valve restraining member, which has a greater bending rigidity than the leaf valve, is adjacent to the back surface, and that the tip of the coil spring is in contact with the back surface of the valve restraining member.

Therefore, in the damping part structure disclosed in Patent Document 1, when the piston speed in the cylinder body is in a very low speed region, the outer peripheral side bending part of the annular leaf valve is flexibly small and a small gap appears. In addition, when the piston speed increases and becomes a medium-high speed region, the valve holding member overcomes the urging force of the coil spring and moves backward, and therefore the outer peripheral side bending portion of the annular leaf valve is large. A large gap appears due to bending, and a predetermined damping action is realized by the hydraulic oil passing through each gap.
JP-A-9-291964 (see paragraphs 0055, 0056, 0062 to 0069, and FIGS. 1 and 3 in the specification)

  However, when the damping part structure disclosed in Patent Document 1 described above including the conventional damping part structure is embodied, if the work is extremely elaborate, the product cost of the hydraulic shock absorber as a product is likely to increase. As a result, there is a risk that the versatility of the hydraulic shock absorber cannot be expected.

  That is, first, in the damping part structure disclosed in the above-mentioned Patent Document 1, a valve restraining member that does not bend at all is adjacent to the back surface of the annular leaf valve. As long as the urging force of the spring is transmitted to the annular leaf valve as it is, the end face at the tip of the coil spring, that is, a flat surface with a frayed finish, is provided on the back of the annular leaf valve as in the previous structure of the damping part. It becomes the same as the end face which consists of a surface is in direct contact.

  Therefore, as will be explained under this premise, when looking at the end face of the coil spring that contacts the back surface of the annular leaf valve, in many cases, the end face consisting of a flat-finished surface of the coil spring is formed around the entire circumference. Thus, the back surface of the annular leaf valve is not in uniform contact with the flat surface, but is actually in contact at two locations that are so-called diametrically strong and weak.

  For this reason, when observing when the outer peripheral side bending portion of the annular leaf valve receiving the urging force from the coil spring starts to bend due to the action of cracking pressure, the urging force from the coil spring is applied to the annular leaf valve. The outer periphery side bending part other than said two places which are the parts which are not received will begin to bend.

  As a result, the operation state set in advance for the annular leaf valve, that is, theoretically, the outer peripheral side bending portion of the annular leaf valve starts to bend uniformly over the entire circumference by the action of cracking pressure. Nevertheless, it cannot be said that the bending state according to this theory is not realized, and therefore it is not desired to generate the damping force as set.

  And in order to overcome this situation, the end face of the coil spring is scraped and finished so-called precisely, so that the end face of the coil spring is spread over the entire circumference on the back surface consisting of the flat surface of the annular leaf valve. It is desirable to ensure uniform contact, but this is not easy in practice, and if it is realized, the cost of parts in the coil spring is increased, and in the hydraulic shock absorber as a product. There is concern that the product cost will increase and its versatility cannot be expected.

  Thus, until now, when the outer peripheral side bent portion of the annular leaf valve starts to bend due to the action of cracking pressure, a phenomenon has occurred that the outer peripheral side bent portion of the annular leaf valve does not bend uniformly over the entire circumference. However, this phenomenon is an instantaneous phenomenon, and thereafter, it can be considered that the outer peripheral side bending portion of the annular leaf valve bends uniformly over the entire periphery, and thus disclosed in the above-mentioned Patent Document 1. In the present situation, the hydraulic shock absorber that embodies the structure of the damping part can realize the generation state of the damping force as set.

  The present invention was devised in view of such a current situation, and the object of the present invention is to solve a point that has not been regarded as a problem so far and to realize a hydraulic shock absorber having a higher degree of perfection. It is possible to provide an attenuation part structure that can be optimized and expected to improve its versatility.

In order to achieve the above object, the means of the present invention includes a cylinder body, a piston rod slidably inserted into the cylinder body via the piston body, and a rod side chamber defined by the piston body in the cylinder body. A piston side chamber, an extension port and a pressure side port formed in the piston body and communicating with the rod side chamber and the piston side chamber, and an annular leaf valve disposed at the downstream end of the extension side port so as to be openable and closable. A valve restraining member that is in contact with the back surface of the leaf valve and has a larger bending rigidity than the leaf valve, a coil spring that is disposed on the back side of the valve restraining member and biases the leaf valve in a closing direction, in the attenuation section structure of a hydraulic shock absorber having a rubbing at the tip of the back and the coil spring consisting of a flat surface of the valve restraining member An elastic body made of a material richer in elasticity than that of the material forming the coil spring is disposed between the cut end-finished flat face and the end face .
In this case, the elastic body is preferably made of a disc spring, or the elastic body is preferably formed in a ring shape from a rubber material or a synthetic resin material.
Similarly, the inner peripheral side fixing portion of the leaf valve may be sandwiched between the inner peripheral side boss portion of the piston body and the upper end of the piston nut carrying the base end of the coil spring, or the annular leaf valve may be It may be movably interposed on the outer periphery of the lower end fitting portion of the piston rod that screws the piston nut that penetrates the shaft core portion of the piston body and carries the base end of the coil spring.

In the invention of each claim, it is more elastic than the elasticity of the material that forms the coil spring between the back surface of the flat surface of the valve restraining member and the end surface of the flat surface that has been scraped off at the tip of the coil spring. Since the elastic body made of a rich material is disposed, the elastic body disperses the urging force that tends to concentrate in two places from the coil spring, so that the annular leaf valve is interposed via the valve holding member. It functions so as to act uniformly on the entire circumference of the back surface.
Therefore, the biasing force of the coil spring is a situation that is transmitted at the site of many made three places or more than two positions with respect to the back of the leaf valve, therefore, the leaf valve is a substantially uniform biasing force in the circumferential direction In the received state, a gap serving as a flow path for the hydraulic oil appears between the piston body and the piston body .

  As a result, according to the present invention, the end face at the tip of the coil spring is subjected to a conventional scraping finish, so that it is not necessary to precisely scrape and finish, and the product cost can be increased without increasing the cost of parts in the coil spring. It becomes possible not to unnecessarily increase the product cost of the shock absorber.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 3 and FIG. 5 show an embodiment corresponding to the invention of claim 1, and FIG. 4 shows a reference example.
The hydraulic shock absorber according to FIG. 1 is defined by a cylinder body 1, a piston rod 2 slidably inserted into the cylinder body 1 via a piston body 3, and the piston body 3 in the cylinder body 1. A rod side chamber R1 and a piston side chamber R2, an extension side port 3a and a pressure side port 3c that are formed in the piston body 1 and communicate with the rod side chamber R1 and the piston side chamber R2, and a downstream end of the extension side port 3a. An annular leaf valve 4 that can be freely opened and closed, a valve restraining member 8 that is in contact with the back surface of the leaf valve 4 and has a larger bending rigidity than the leaf valve 4, and a back surface side of the valve restraining member 8. And a coil spring 5 for urging the leaf valve 4 in the closing direction.
Further, it is formed of a material richer in elasticity than the elasticity of the material forming the coil spring between the back surface made of a flat surface of the valve restraining member 8 and the end surface made of a flat-finished surface at the tip of the coil spring 5. The elastic body 9 is provided.
This will be described in detail below.

  That is, in the hydraulic shock absorber, even if the hydraulic shock absorber is formed as a single cylinder type or a double cylinder type, the cylinder body 1 has a lower end which is the lower end side in the figure of the piston rod 2 which is a rod body. It is said that the side is inserted so that it can appear and disappear.

  The lower end fitting portion 2a of the piston rod 2 positioned in the cylinder body 1 holds a piston portion slidably accommodated in the cylinder body 1, and at this time, the piston portion The piston body 3 that is a valve seat member that forms a cylinder body 1 defines a rod-side chamber R1 that is upstream and a piston-side chamber R2 that is downstream.

  In addition, the piston body 3 is formed by opening the expansion side port 3a that is a flow path that allows the rod side chamber R1 to communicate with the piston side oil R2, and the downstream side that is the lower end in the drawing of the expansion side port 3a. The side end is closed so as to be openable and closable by an annular leaf valve 4 which is a valve body which is an extension side damping valve.

  At this time, the annular leaf valve 4 is seated on the piston body 3 by the urging force of the coil spring 5 disposed on the back side of the annular leaf valve 4, and closes the above-mentioned extension side port 3a. It is said.

  The coil spring 5 is assumed to be carried by a lower end flange 6a of a piston nut 6 screwed into a lower end fitting portion 2a of the piston rod 2 as shown in the drawing. The piston nut 6 is configured such that the inner peripheral side fixing portion 4a of the annular leaf valve 4 is sandwiched between the piston nut 6 and the inner peripheral side boss portion 3b of the piston body 3 at the upper end thereof.

  Incidentally, the arrangement state of the annular leaf valve 4 to the piston body 3 is considered. From the point of view of the present invention, the annular leaf valve 4 penetrates the shaft core portion of the piston body 3 and the coil spring 5 The piston rod 6 carrying the base end may be provided in a floating structure that is movably interposed on the outer periphery of the lower end fitting portion 2a of the piston rod 2 on which the piston nut 6 is screwed.

  Further, in the illustrated embodiment, the piston body 3 includes a pressure side port 3c that is a flow path that allows the piston side chamber R2 to communicate with the rod side chamber R1, and an upper end of the pressure side port 3c in the drawing. The downstream end is closed with an annular leaf valve 7 serving as an extension check valve so as to be opened and closed.

  At this time, the annular leaf valve 7 is energized from the back side by the non-return spring 7a and is seated on the piston body 3. However, the flow of the hydraulic oil from the rod side chamber R1 to the extension side port 3a is prevented. An opening 7b is provided so as not to exist.

  Therefore, in the piston portion formed as described above, when the piston body 3 that is the valve seat member moves upward in the cylinder body 1, the hydraulic oil in the rod side chamber R1 that is the upstream side is moved to the piston body 3. The bent portion of the annular leaf valve 4 as a valve element that flows into the opening side port 3a of the opening and closes the downstream end of the extension side port 3a so as to be openable and closable is resisted against the biasing force of the coil spring 5. Thus, a gap appears between the piston body 3 and the hydraulic oil flows out into the piston side chamber R2 on the downstream side through this gap, and a predetermined extension side damping force is generated. It will be.

  Incidentally, as will be described later, in the illustrated embodiment, the outer peripheral side bending portion of the annular leaf valve 4 bends without bending the coil spring 5 when the piston speed is in the very low speed region. An extension side damping force of the region is generated.

  Contrary to the above, at the time of pressure side operation in which the piston body 3 descends in the cylinder body 1, the hydraulic oil in the piston side chamber R2 flows into the pressure side port 3c of the piston body 3 and the downstream side of the pressure side port 3c. The annular leaf valve 7 serving as a check valve that closes the end in an openable / closable manner is bent to cause a gap between the piston body 3 and the hydraulic oil flows into the rod side chamber R1 through this gap.

  Incidentally, it is assumed that the compression side damping force at the time of the compression side operation is generated in a base valve portion (not shown) disposed at the bottom end portion of the cylinder body 1 in many cases.

  By the way, in the above-described piston portion, the coil spring 5 urges the annular leaf valve 4 from the back side. However, in the illustrated embodiment, a valve holding member 8 is provided on the back surface of the annular leaf valve 4. Therefore, the tip that is the upper end of the coil spring 5 in the drawing is basically in a state of biasing the annular leaf valve 4 through the valve restraining member 8. .

  Incidentally, the valve restraining member 8 is formed so as not to be easily bent with a material having a bending rigidity larger than that of the annular leaf valve 4, and the outer diameter is made smaller than the outer diameter of the annular leaf valve 4. It is assumed that it is adjacent to the back surface of the valve 4.

  The outer diameter of the valve restraining member 8 may be substantially the same as the outer diameter of the annular leaf valve 4. In this case, the outer diameter of the annular leaf valve 4 is smaller than that in the above case. Thus, the outer peripheral side bent portion in the annular leaf valve 4 is further suppressed, and therefore, the outer peripheral side bent portion in the annular leaf valve 4 will be difficult to be bent in a very low speed region.

  As described above, in the illustrated embodiment, the coil spring 5 basically urges the annular leaf valve 4 from the back side via the valve restraining member 8. However, in order to embody the present invention. In addition, an elastic body 9 is provided between the tip of the coil spring 5 and the back surface of the valve holding member 8.

  Therefore, the elastic body 9 and the function of the elastic body 9 will be described below. First, the elastic body 9 is a material richer in elasticity than the elasticity of the material forming the coil spring 5. It is supposed to be formed by.

  As shown in principle in FIG. 2, this is composed of a flat surface of the coil spring 5 that is scraped and finished when the elastic body 9 is not provided between the coil spring 5 and the annular leaf valve 4 that is the valve body. As described above, the end surface of the annular leaf valve 4 comes into contact with the back surface of the flat surface, and as described above, there are two radial positions on the end surface of the coil spring 5. As described above, one of them is in strong contact with the annular leaf valve 4 and the other is in weak contact with the annular leaf valve 4.

  For this reason, when observing when the outer peripheral bending portion of the annular leaf valve 4 receiving the urging force from the coil spring 5 starts to bend due to the action of cracking pressure, the annular leaf valve 4 As described above, the outer peripheral side flexures other than the above two strengths, which are portions not receiving the urging force from the spring 5, start to bend.

  Therefore, in the present invention, an elastic body 9 is provided between the coil spring 5 and the annular leaf valve 4 as shown in principle in FIG. It is assumed that the urging force of the spring 5 acts on the annular leaf valve 4.

  At this time, it is assumed that the elastic body 9 is formed of a material richer in elasticity than the elasticity of the material forming the coil spring 5. Therefore, the elastic body 9 tends to concentrate in two places from the coil spring 5. The urging force is distributed so as to act uniformly on the entire circumference of the back surface of the annular leaf valve 4.

  Therefore, on the back surface of the annular leaf valve 4, the urging force from the coil spring 5 acts on three or more parts more than two places, and therefore, a situation that acts uniformly on the entire circumference is present. Will be issued.

  Incidentally, for example, when the elastic body 9 is formed by forming a flexible pipe body filled with fluid in a ring shape, if the urging force of the coil spring 5 is applied to the elastic body 9, the elastic body 9 is elastic. It can be said that the body 9 is apparent from the fact that the biasing force is made uniform and acts on the annular leaf valve 4.

  Therefore, in the present invention, the end face of the coil spring 5 is more precisely scraped and finished so that the urging force from the coil spring 5 acts uniformly on the back surface of the annular leaf valve 4 in the circumferential direction. Therefore, it is possible to avoid an unnecessarily high part cost in the coil spring 5.

  As described above, when the outer peripheral side bent portion of the annular leaf valve 4 starts to bend due to the action of cracking pressure, the outer peripheral side bent portion of the annular leaf valve 4 extends over the entire circumference. Even if a phenomenon that does not bend uniformly is expressed, this phenomenon is an instantaneous phenomenon, and thereafter, it will be considered that the outer peripheral side bending portion of the annular leaf valve 4 bends uniformly over the entire circumference. Because, as a whole, it was possible to embody the state of occurrence of damping force as set as a whole, the present invention can actively solve the problems that were previously ignored, A more highly complete hydraulic shock absorber can be provided.

  In view of the above, it is sufficient that the elastic body 9 is disposed between the coil spring 5 and the annular leaf valve 4. From this point of view, as shown in FIG. The poppet 10 may be arranged between the back surface of the flat surface of the poppet 10 and the end surface of the flat surface of the coil spring 5 which is scraped off.

  Incidentally, at this time, the poppet 10 closes the opening of the flow path so that the valve seat member can be opened and closed by the urging force of the coil spring 5 while the tip of the valve seat member is in the open flow path.

  The elastic body 9 may be disposed between the annular leaf valve 4 and the valve holding member 8 as shown in FIG. 5, and at this time, the annular leaf valve 4 is connected to the aforementioned FIG. As in the case of the illustrated embodiment, the downstream end of the opening side port 3a for opening the piston body 3 is closed so as to be openable and closable.

  In the present invention, it is sufficient that the elastic body 9 is basically made of a material richer in elasticity than the elasticity of the material forming the coil spring 5. As shown in (A) of FIG. 6, the ring-shaped bodies 92 and 93 are made of a disc spring 91, or are made of rubber or synthetic resin as shown in (B) and (C) of FIG. It is good to be formed.

  As described above, when the elastic body 9 is composed of the disc spring 91 or the ring-shaped bodies 92 and 93, it will be advantageous in that it can be easily obtained as a part. In the bodies 92 and 93, instead of the so-called cross section of the line being a square shown by a solid line diagram, it is a rectangle shown by a broken line figure, or instead of being a circle shown by a solid line figure. Any cross-sectional shape such as an oval shape shown in the diagram may be selected.

  That is, for example, a trapezoidal cross section having an outer peripheral surface as an inclined surface like an elastic body 94 shown in FIG. 7A and an outer peripheral surface facing a so-called face like an elastic body 95 shown in FIG. However, the inner circumferential surface may have a convex arcuate surface, and the inner circumferential surface may have a mountain shape while facing the outer circumferential surface as shown in FIG. In this case, it is advantageous in that a so-called proper use can be made according to the mode of the valve body as the annular leaf valve 4.

It is a fragmentary longitudinal cross-section which shows the piston part in the cylinder in the hydraulic shock absorber which actualized the damping | damping part structure by this invention. It is a principle figure which shows the transmission state to the valve body of the urging | biasing force from a coil spring. It is a figure which shows the transmission state to the valve body of the urging | biasing force from the coil spring in the case by this invention similarly to FIG. It is a partial longitudinal cross-sectional view of the attenuation | damping part structure concerning a reference example . FIG. 2 is a semi-circular view showing an embodiment in which an elastic body is disposed between a spring restraining member and a valve body as in FIG. 1. (A), (B) and (C) are sectional views of an elastic body, respectively. (A), (B) and (C) are respectively half-ridge cross-sectional views of an elastic body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder body 2 Piston rod 2a Lower end fitting part 3 Valve seat member (piston body)
3a Extension side port (flow path)
4 Annular leaf valve (valve)
5 Coil spring 6 Piston nut 8 Valve restraining member 9 Elastic body 10 Poppet R1 Rod side chamber (upstream side)
R2 Piston side chamber (downstream side)

Claims (3)

A cylinder body, a piston rod slidably inserted in the cylinder body via a piston body, a rod side chamber and a piston side chamber separated by the piston body in the cylinder body, and the rod side chamber formed in the piston body An expansion-side port and a pressure-side port that communicate with the piston-side chamber, an annular leaf valve that can be opened and closed at the downstream end of the expansion-side port, and a leaf valve that is in contact with the back surface of the leaf valve. a member suppress flexural rigidity is large valve, the damping unit structure in the hydraulic shock absorber and a coil spring for biasing the closing direction the leaf valve disposed on the rear side of the valve restraining member, suppresses the valve carp between the end face made of the finished flat surface leveling at the tip of the back and the coil spring consisting of a flat surface of the member A damping part structure in a hydraulic shock absorber, wherein an elastic body made of a material richer in elasticity than a material forming a spring is disposed . The damping part structure according to claim 1, wherein the elastic body is made of a disc spring, or the elastic body is formed in a ring shape from a rubber material or a synthetic resin material . The inner peripheral side fixed portion of the leaf valve is sandwiched between the inner peripheral side boss portion of the piston body and the upper end of the piston nut that carries the base end of the coil spring, or the leaf valve is the shaft core portion of the piston body 3 The damping part in the hydraulic shock absorber according to claim 1 or 2, wherein the damping part is movably interposed on the outer periphery of the lower end fitting part of a piston rod screwing a piston nut carrying the base end of the coil spring through the shaft. Construction.

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