JP2004255615A - Resin molding and valve structure using the same - Google Patents

Abstract

An object of the present invention is to provide a resin molded body that can ensure high molding accuracy of a valve portion of a valve body when a resin molded body, for example, a valve body is molded by injection molding.
A valve body (5) slidably provided inside a valve body, and a valve seat with which a valve portion (10a) of the valve body comes into contact with or separates from the valve body. Molded from resin material. The tip openings 25a, 26a of the pair of gate portions 25, 26 of the injection molding machine are formed in the vicinity of the valve portion forming portion 23c of the cavity 23 for forming the valve portion of the valve body, and are formed in the second cavity portion 23b. The molten resin injected into the valve portion is caused to flow along the inner peripheral surface of the valve portion forming portion, thereby improving the transferability of the molten resin to the inner peripheral surface of the valve portion forming portion which is the outer peripheral surface of the valve portion.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a resin molded body applied to, for example, a valve body of an electromagnetic valve of an anti-lock brake system for controlling a brake fluid pressure of a vehicle, and a valve structure using the same.
[0002]
[Prior art]
As a conventional valve structure of this kind, there is known a valve structure described in Patent Literature 1 below which is applied to an electromagnetic valve of an antilock brake system.
[0003]
In brief, the solenoid valve is formed in a passage forming body and has a valve housing hole in which a working fluid passage is opened, and is housed and fixed in the valve housing hole, and can communicate with the working fluid passage. A metal valve seat having a passage hole and a metal plunger integrally provided with a valve body for opening and closing the passage hole of the valve seat are provided, and a cylinder is slidably housed in the plunger. . A fixed core is fixed to one end of the cylinder, and an electromagnetic coil is arranged on the outer periphery of the fixed core. Further, the plunger is urged in the opening direction by the spring force of a valve spring provided on the valve body side, and is a so-called normally-open solenoid valve.
[0004]
[Patent Document 1] Japanese Patent Publication No. 2000-517264
[Problems to be solved by the invention]
However, in the above-described conventional solenoid valve structure, since the valve body and the valve seat are formed of metal, a tapping sound is generated when the valve body is opened and closed (seated) with respect to the valve seat, and vehicle noise is generated. Is conducive to.
[0006]
Therefore, it is conceivable that one of the valve body and the valve seat is formed of a synthetic resin material or the like to suppress generation of a seating hitting sound. For example, when the valve body is formed of a synthetic resin material by injection molding, Since the valve portion at the tip, which is the contact portion of the valve body with the valve seat, has a relatively small projection, it is difficult to achieve high molding accuracy of the valve portion.
[0007]
As a result, the closing accuracy of the valve portion with respect to the passage hole of the valve seat at the time of closing the valve is deteriorated, and oil leakage may occur.
[0008]
The present invention has been devised in view of the above-mentioned conventional technical problem, and when a resin body, for example, a valve body is molded by injection molding, a resin capable of ensuring high molding accuracy at the distal end of the valve body. It is intended to provide a molded article.
[0009]
[Means for Solving the Problems]
In the invention according to claim 1, in particular, the resin molded body is molded by injection molding, and the gate is arranged in the vicinity of the high precision required part of the cavity for molding the resin molded body, and the resin is molded into the cavity. It is characterized by being molded from the injected molten resin.
[0010]
According to the present invention, when the resin molded body is injection-molded, the molten resin material is directly supplied to the molding portion of the cavity for molding the high precision required portion via the gate portion. The supply pressure of the molten resin to the part where the part is formed is increased, and therefore, the transferability of the molten resin to such a part is improved.
[0011]
The invention according to claim 2 is that, in particular, the valve body or the valve seat is formed by injection molding, and the valve body or the valve seat is formed from a gate portion arranged near a contact portion forming portion of a cavity for forming the valve body or the valve seat. It is characterized by being molded by molten resin injected into the cavity.
[0012]
According to the present invention, it is possible not only to suppress the occurrence of a tapping sound when the valve body is seated on the valve seat, but also, when the valve body or the valve seat is injection-molded, through the gate portion. Since the molten resin material is directly supplied to the molding portion of the cavity for molding the contact portion, the supply pressure of the molten resin to the molding portion of the contact portion of the cavity is increased, and therefore, the molten resin is supplied to the molding portion. Transferability is improved.
[0013]
As a result, for example, the molding accuracy of the distal end portion (contact portion) of the relatively small valve element is increased, the adhesion when seated on the valve seat is improved, and high sealing performance can be secured.
[0014]
The invention according to claim 3 is characterized in that the cavity is formed by a molten resin injected into the cavity from an opening of the gate portion, which is directed toward a contact forming region of the cavity.
[0015]
According to the present invention, since the opening of the gate portion is formed so as to face the contact portion forming portion of the cavity, it is possible to further increase the pressure of the molten resin to the corresponding contact portion forming portion. Thus, the transferability of the molten resin to the molding site can be further improved.
[0016]
According to a fourth aspect of the present invention, a fixed core fixed to the inner peripheral side of an electromagnetic coil provided inside the valve body, and slides axially into the valve body through the attraction force of the fixed core. A valve body provided freely, and a valve seat having a passage hole formed in an inner axial direction, the valve body being detachably seated on an opening edge of the passage hole and being opened and closed, wherein the valve body is made of synthetic resin. It is characterized by being formed of a material.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which a resin molded body according to the present invention is applied to a valve body of a solenoid valve of an antilock brake system will be described in detail with reference to the drawings.
[0018]
As shown in FIG. 3, the solenoid valve has a valve holding hole (not shown) formed inside an aluminum alloy housing, and a fixed cylindrical shape having a tip 1a housed in the valve holding hole. , A cylindrical electromagnetic coil 2 disposed on the outer peripheral side of one end of the valve body 1, and fixed between the cylindrical inside of the electromagnetic coil 2 and the valve body 1. A metal cylinder 3 having a bottomed cylindrical shape, a plunger 4 which is a metal movable core slidably housed inside the cylinder 3, and is coaxially abutted and arranged at the tip of the plunger 4. A valve body 5 which is a resin molded body, and a cylindrical valve seat 6 which is housed and fixed inside the distal end portion 1a of the valve body 1 and on which the valve body 5 is separated and seated in the axial direction.
[0019]
The valve body 1 has a flange-like substantially central portion 1b fixed to a hole edge of the valve holding hole by caulking or the like, and a holding hole 1c for slidably holding the valve body 5 is formed therein. Have been. A supply hole 8 for supplying the brake fluid to the wheel cylinder via a filter 7 is formed through the side wall of the tip 1a.
[0020]
The electromagnetic coil 2 is supplied or interrupted with a control current by a controller (not shown) for inputting detection information such as a vehicle speed and a wheel slip state, thereby deenergizing the valve body 1. .
[0021]
The plunger 4 is formed in a substantially cylindrical shape, and slides axially in the cylinder 3 between clearances C formed between a front end face and one end face of the valve body 1.
[0022]
The valve body 5 is integrally formed of a synthetic resin material as described above, and as shown in FIGS. 3 and 4, a sliding portion 9 that slides in the holding hole 1b, And a tapered shaft 10 at the tip. Further, the valve element 5 is urged in the direction of the plunger 4 (valve opening direction) by a valve spring 11 elastically mounted between a front end portion of the valve seat 6 and a front end surface of the shaft portion 10.
[0023]
As shown in FIG. 5, the sliding portion 9 is formed in a bipartite shaft shape in cross section, and includes four projections 9a to 9d radially from the axis, and the outer peripheral surface of each of the projections 9a to 9d is substantially in cross section. It is formed in an arc shape, and comes into sliding contact with the holding hole 1c in a line contact state. Therefore, the sliding friction resistance is reduced, and the slidability of the valve element 5 is improved.
[0024]
As shown in FIG. 4, the shaft portion 10 is formed in a tapered shape from a base end portion on the sliding portion 9 side to a tip end portion, and has a spherical shape which is a contact portion with the tip end portion. Is formed.
[0025]
As shown in FIGS. 3 and 4, the valve seat 6 is formed of a metal material in a substantially cylindrical shape, and brake fluid from a master cylinder (not shown) is supplied to the supply hole 8 via a filter 12 in an internal axial direction. A passage hole 13 for inflow is formed therethrough, and a valve portion 10a of the valve body 5 is detached and seated on the edge of the opening of the passage hole 13 formed at the tip end projecting portion. A substantially spherical seat 6a to be opened and closed is formed.
[0026]
The synthetic resin valve element 5 is formed by a mold 20 shown in FIGS. The mold 20 includes a lower mold 21 and an upper mold 22, and a cavity 23 is formed over the lower mold 21 and the upper mold 22.
[0027]
The cavity 23 is formed in the lower mold 21 and forms a first cavity 23a for molding the sliding portion 9, and the second mold is formed in the upper mold 22 and forms the shaft 10 and the valve 10a. And a cavity 23b. The second cavity portion 23b has a molded portion 23c formed on the distal end side, which has a spherical inner peripheral surface for molding the valve portion 10a of the shaft portion 10.
[0028]
The lower mold is formed with a pair of runner portions 24, 24 that communicate with the second cavity portion 23b via gate portions 25, 26 described later. The gate portions 25 and 26 have front end openings 25a and 26a directed toward the front end of the second cavity 23b, and base ends 25b and 26b open to the runner portions 24 and 24, respectively.
[0029]
Therefore, according to this embodiment, when the valve body 5 is molded by the mold 20, molten resin is applied from the respective runner portions 24, 24 to the base ends 25b, 26b of the respective gate portions 25, 26. It is pumped by an external pumping means. The molten resin that has flowed into each of the gate portions 25 and 26 is pressure-fed directly from the distal end openings 25a and 26a to the molding portion 23c of the valve portion 10a as indicated by arrows in FIG.
[0030]
For this reason, the molten resin flows along the inner peripheral surface of the molding portion 23c of the second cavity portion 23b, and then slides on the shaft portion 10 molding portion of the second cavity portion 23b and the first cavity portion 23a. The fluid flows into the molding portion 9 and spreads over the entire cavity 23.
[0031]
After that, if the resin molded body of the valve body 5 is taken out through a cooling step, the molding operation is completed.
[0032]
Although a pair of gate portions 25 and 26 are provided, if a high supply pressure is not required, one gate portion may be provided.
[0033]
As described above, in this embodiment, since the molten resin is directly supplied from the two gates 25 and 26 to the molding portion 23c of the second cavity 23b for molding the valve portion 10a, the supply pressure increases. The transferability of the molten resin material at the molding portion 23c is improved.
[0034]
As a result, the accuracy of the spherical outer surface of the relatively small valve portion 10a is increased, and the tightness of the valve seat 6 when seated on the seating surface 6a is improved, so that high sealing performance can be secured.
[0035]
In particular, in this embodiment, since the tip openings 25a and 26a of the gate portions 25 and 26 are formed so as to face the molding portion 23c of the valve portion 10a of the cavity 23, the molten resin is injected into the molding portion 23c. The pressure can be further increased, and the transferability of the molten resin to the molding portion 23c can be further improved.
[0036]
Further, as shown in FIG. 1, since the gate portions 25 and 26 are formed to face upward to the valve body forming portion 23c, gas discharged from the molten resin and air in the cavity 23 are discharged from the cavity 23. The transferability is further improved.
[0037]
Further, since two gate portions 25 and 26 are provided to supply the molten resin material into the second cavity portion 23b from a position facing each other, the supplied molten resin materials interfere with each other at the valve portion forming portion 23c. Since the molten resin flows along the inner peripheral surface in the kneaded state, the transferability of the molten resin to the valve molding portion 23c is further improved. In addition, since the supplied molten resin material is sufficiently agitated while sufficiently interfering with the entire interior of the cavity 23 and spread over the entire cavity 23, it is possible to mold the valve element 5 (resin molded body) with high density and accuracy. become.
[0038]
The present invention is not limited to the configuration of the above embodiment, and the shape of the valve body can be variously selected.
In addition, the resin molded body can be applied not only to a valve body of an electromagnetic valve but also to a valve seat, and can also be applied to a resin molded article having a high precision required part which is not applied to a valve structure. .
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a state in which a valve element provided in an embodiment of the present invention is molded by a mold.
FIG. 2 is a schematic plan view of a mold provided in the embodiment.
FIG. 3 is a longitudinal sectional view of the solenoid valve structure of the embodiment.
FIG. 4 is an enlarged sectional view showing a state in which the valve body is separated from a valve seat.
FIG. 5 is a plan view of a valve body provided in the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Valve body 4 ... Plunger 5 ... Valve body 6 ... Valve seat 10a ... Valve part 23 ... Cavity 23c ... Valve molding part (high precision required part)
25 ・ 26… Gate

Claims (4)

In a resin molded body molded with a synthetic resin material and having a high precision required part at least in part compared to other parts,
The resin molded body is molded by injection molding, and is molded by a molten resin injected into the cavity from a gate portion arranged near the high precision required portion of the cavity for molding the resin molded body. Resin molding. A valve body slidably provided inside the valve body, and a valve seat with which the valve body comes into contact with or separates from the valve body, and at least one of the valve body and the valve seat is formed of a synthetic resin material. In the valve structure
The valve body or the valve seat is formed by injection molding, and is formed by molten resin injected into the cavity from a gate portion disposed near the contact portion forming portion of the cavity for forming the valve body or the valve seat. A valve structure characterized by: 3. The valve structure according to claim 2, wherein the valve structure is formed by a molten resin injected into the cavity from an opening of the gate portion, which is directed toward a contact portion forming portion of the cavity. 4. A fixed core fixed to the inner peripheral side of an electromagnetic coil provided inside the valve body, and a valve body slidably provided inside the valve body in the axial direction via the attraction force of the fixed core; A valve hole formed in the inner axial direction, the valve body being provided with a valve seat that is opened and closed by being seated at an opening edge of the passage hole, wherein the valve body is formed of a synthetic resin material. The valve structure according to claim 2.

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