JPH09103838A - End surface forming method for shaft member and electric magnet valve for abs using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely keep a required surface roughness on a spherical sea surface without executing an expensive additional working, and to enlarge an effective sealing surface and also a guide length. SOLUTION: In the case of forming a shaft 68 of front sub-solenoid valve for ABS, a recessed part 84 is formed at the end part of a blank 82 being a solid shaft, then the blank 82 is fixed to a die 86 and a punch 88 having a semispherical recessed part 90 is applied thereto. Next, the circumferential part 92 of the recessed part 84 is padded by cold forging. Thereafter, a pads part 94 is removed by lathing (or press punching). Thus, the padding resistance is reduced, the effective sealing surface and the guide length can be enlarged, and the required surface roughness can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end face forming method for a shaft member and an ABS solenoid valve using the same.

[0002]

2. Description of the Related Art Conventionally, a plunger has been widely used as a valve body for opening and closing an oil passage. A method for manufacturing a plunger of this type is disclosed in Japanese Patent Laid-Open No. 1-133
It is disclosed in Japanese Patent No. 634, which will be briefly described below. The plunger manufactured by the manufacturing method disclosed in this publication is used for a valve lash adjuster.

First, as shown in FIG. 4 (A), a bottomed cylindrical material 100 is manufactured. At this time, the valve seat 102 and the oil hole 104 for the check ball are formed on the bottom portion, and the tapered portion 106 is formed on the outer periphery of the tip portion by forging or cutting. Further, a side surface oil hole 107 is formed in the axially intermediate portion of the raw material 100.

Next, as shown in FIG. 4 (B), the tapered stopper step portion 108 is formed on the tip end side by drawing the material 100 which has undergone the above-mentioned steps. This processing is performed by fixing the material 100 to a die having a drawing land and applying an impact to the material 100 with a punch. Further, at this time, a tapered inner peripheral taper portion 110 is formed at the tip portion of the material 100 by cold forging.

Next, the material 100 after the above steps is fixed to a die having another drawing land, and the material 100 is punched.
Give a shock to. As a result, as shown in FIG. 4C, the material 100 is reduced in outer diameter, and the shoulder 112 is formed on the stopper step 108 described above.

Next, after the material 100 which has undergone the above steps is turned upside down and fixed to a die, the inner peripheral taper portion 11 of the material 100 is punched by a punch having a die whose inner peripheral surface is a hemispherical surface.
Add a shock to 0. As a result, as shown in FIG. 4D, the inner peripheral tapered portion 110 is drawn into a spherical shape having the oil hole 113 in the axial center portion, and the plunger 114 for the valve lash adjuster is configured.

However, in the case of the above molding method,
Since this is a method of forming the tip of the material 100 into a spherical shape by drawing, it is not possible to secure the required surface roughness of the spherical surface, and additional processing with high cost such as grinding is required.

On the other hand, the plunger is also manufactured by cold forging, which will be briefly described below. First,
As shown in FIG. 5A, the material 120, which is a solid shaft.
After being fixed to the die 122, a punch 126 having a hemispherical recess 124 is applied. Next, as shown in FIG. 5B, pressure is applied to remove the meat at the tip of the material 120 into the recess 1
It gathers along the inner surface of 24. As a result, a shaft (plunger) 128 having a hemispherical tip is formed.

However, in the case of the above molding method,
When the tip end of the material 120 is pressed against the inner peripheral surface of the recess 124, the contact resistance is large. Therefore, the meat does not reach the top of the recess 124, and the uncontacted portion 130 of the meat to the recess 124 is formed. Occurs. In addition, a non-contact portion 132 of the meat with the die is also generated at the tangent portion between the die 122 and the punch 126. From these things, in the case of this molding method, the effective range as the sealing surface can be obtained only in the range shown by S ′, and the effective sealing surface is narrowed, and the sealing property may be deteriorated. Further, since the non-contact portion 132 is generated, the guide length when the shaft (plunger) 128 is moved in the axial direction is shortened, and the axial line of the plunger is easily displaced during valve operation, so that a predetermined valve performance can be achieved. Becomes difficult.

In consideration of the above facts, the present invention can secure the required surface roughness of the spherical sealing surface without performing additional processing at high cost, and further expand the effective sealing surface and the guide length. An object of the present invention is to obtain an end face forming method for a shaft member and a solenoid valve for ABS using the same.

[0011]

According to a first aspect of the present invention, there is provided a method for forming an end surface of a shaft member according to the present invention, which comprises a first step of forming a concave portion at an axial center portion of an end portion of a material which is a solid shaft, A second step of forming the end face of the material into a spherical shape by reducing the thickness of the periphery of the recess of the material by cold forging.

According to a second aspect of the present invention, in the end face forming method for a shaft member according to the first aspect of the present invention, in the invention according to the first aspect, after the second step, the extra thickness generated in the circumferential direction of the material is cut off. It is characterized in that the third step is performed.

According to a third aspect of the present invention, there is provided an ABS solenoid valve having a shaft member having a spherical end face formed by the method according to the first or second aspect, which is used as an ABS solenoid valve. It is used as a valve body.

According to the first aspect of the present invention, in the first step, the recess is formed in the axial center portion of the end portion of the material which is the solid shaft. Next, in a second step, the end surface of the material is formed into a spherical shape by cold forging while the periphery of the recess of the material is reduced.

As described above, according to the present invention, since the concave portion is provided in the end portion of the raw material in advance and the periphery of the concave portion of the raw material is brought closer by cold forging, the meat can be formed without the concave portion. Compared with the case of bringing them together, the resistance to meat gathering is reduced. For this reason, the meat around the concave portion is sufficiently spread to the spherical top, and the area of the meat per die is increased. Therefore, the range effective as the sealing surface is expanded.

Further, in the process of forming the end surface of the material into a spherical shape by cold forging, the meat flows in a direction substantially orthogonal to the mold surface, so that the required surface roughness of the sealing surface is secured. Therefore, there is no need to perform additional processing such as grinding which is costly.

According to the second aspect of the present invention, after the second step described above is performed, the excess thickness generated in the circumferential direction of the material is cut off, so that the following action can be obtained. That is, in general, in order to form so that excess thickness is not generated, the diameter of the material corresponding to the abutting position of the die and the punch is made thin, but by doing so, the meat escapes to the portion with a small diameter. Therefore, there is a disadvantage that the necessary spherical contact portion cannot be secured because the spherical seal portion is not thickened. However, in the present invention, after intentionally generating a surplus when forming the end surface of the material into a spherical shape by cold forging,
Since this is cut off, it is not necessary to reduce the diameter of the material as described above. For this reason, the meat is sufficiently brought close to the spherical seal portion, and the required spherical contact portion is also secured.

Further, as described above, if the diameter of the material is reduced (provided that the material has a small diameter portion), when the manufactured shaft member is used as a valve body of the valve, the small diameter portion has a shaft member (valve). Since it is not in contact with the guide means for guiding the axial movement of the body, the function as the axial sliding guide portion of the shaft member cannot be obtained. For this reason, the axis of the shaft member and the guide means are easily displaced, and it becomes difficult to secure the predetermined performance as a valve. However, according to the present invention, since a surplus portion is generated and cut off, that is, since such a small diameter portion is not formed in the shaft member, the guide length of the shaft member becomes long, and the axial sliding of the shaft member becomes large. The function as a motion guide unit is secured. Therefore, it is possible to ensure a predetermined performance as a valve.

According to the present invention of claim 3, claim 1
Alternatively, since the shaft member having the spherical end face formed by the method according to the second aspect is used as the valve body of the solenoid valve for ABS, the sealing property of the solenoid valve used for ABS is improved. Further, since the guide length of the shaft member becomes long, there is no rattling during operation.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 3 shows a layout of an oil passage for a front wheel system of an automobile ABS. As shown in this figure, the ABS actuator 10 includes a front main solenoid valve 12 and a front sub solenoid valve 1.
4, reservoir 16, a plurality of check valves 18, 20,
22 and a pump 24 and the like.

The front main solenoid valve 12 is
It is connected to the master cylinder 28 via the A port 26. The front main solenoid valve 12 is
It is connected to the reservoir 16 via the B port 30.
Further, the front sub-solenoid valve 14 is connected to the front wheel cylinder 34 via the C port 32. The front main solenoid valve 12 and the front sub solenoid valve 14 communicate with each other via a port 35. The front main solenoid valve 12, the front sub solenoid valve 14, and the pump 24 have a speed sensor 36 and a G sensor.
AB that operates based on the signal input from the sensor 37
It is adapted to be driven by a drive signal from the S computer 38. The arrows in this figure show the flow of fluid during normal braking (when ABS is not operating).

The operation of the ABS having the above-described structure will be briefly described. During normal braking, since the control signal from the ABS computer 38 is not input, the A port 26 side of the front main solenoid valve 12 is opened and the B port 30 side is closed. To be done. Therefore, when the brake pedal 40 is depressed to increase the hydraulic pressure in the master cylinder 28, the fluid is supplied to the front wheel cylinder 34 via the A port 26 and the C port 32.

At the time of sudden braking (at the time of ABS operation), in the sudden depressurization mode, "abrupt decompression" from the ABS computer 38 is performed.
A signal of the front main solenoid valve 12
The port 26 side is closed and the B port 30 side is opened. Further, the C port 32 side of the front sub solenoid valve 14 is opened. Therefore, the fluid of the front wheel cylinder 34 is fed to the reservoir 16 via the C port 32 and the B port 30. The fluid stored in the reservoir 16 is pumped out by the pump 24 and returned to the master cylinder 28. In the slow depressurization mode, the "slow depressurization" signal from the ABS computer 38 also closes the C port 32 side of the front sub-solenoid valve 14. Therefore, the fluid is C port 3
It will also flow through the two flanking orifices.

In the rapid pressure increase mode, the "a sudden pressure increase" signal from the ABS computer 38 opens the A port 26 side of the front main solenoid valve 12 and closes the B port 30 side. Further, the C port 32 side of the front sub solenoid valve 14 is opened. Therefore, the fluid of the master cylinder 28 is fed to the front wheel cylinder 34 via the A port 26 and the C port 32. In the slow pressure increasing mode, the "slow pressure increasing" signal from the ABS computer 38 also closes the C port 32 side of the front sub-solenoid valve 14. Thus, the fluid will likewise flow through the orifice beside the C port 32.

FIG. 2 shows the ABS actuator 1 described above.
The sectional structure of the front sub-solenoid valve (electromagnetic valve) 14 used in No. 0 is shown, and the structure of the front sub-solenoid valve 14 will be described below with reference to this drawing.

The front sub-solenoid valve 14 has a bottomed cylindrical sleeve 50. The end of the sleeve 50 on the open side is expanded in diameter to form an expanded diameter portion 50A.

A cylindrical guide member 52, which also functions as a core, is fixed to the enlarged diameter portion 50A side of the sleeve 50. A through hole 54 is formed in the axial center of the guide member 52. A valve chamber 56, which has a larger diameter than the through hole 54 and communicates with the through hole 54, is formed at the end of the guide member 52. Further, communication holes 58, 60 facing each other and communicating with the valve chamber 56 are formed on the peripheral wall of the end portion of the guide member 52. The communication holes 58 and 60 are communicated with the port 35 described above.

In the valve chamber 56 of the sleeve 50 described above,
A cylindrical seat valve 62 is fitted. A communication passage 64 that communicates with the valve chamber 56 is formed at the axial center of the seat valve 62. The communication passage 64 communicates with the C port 32 described above. Further, at the tip of the communication passage 64 of the seat valve 62, the dish-shaped seat surface 62 is formed.
A is formed. Further, a cup seal 66, which is an elastic body, is fitted on the outer periphery of the rear end portion of the seat valve 62.

Further, the through hole 54 of the sleeve 50 described above.
Inside, a shaft (plunger) 68 is supported in an inserted state. A columnar block 70 is fixed to one end of the shaft 68. The outer periphery of the sleeve 50 (the outer periphery of the block 70) has a yoke 7 having a substantially rectangular cross section.
2 is arranged, and further, a drum-shaped inner yoke 74 is arranged inside thereof. A coil 76 is arranged on the outer peripheral portion of the inner yoke 74.

The other end of the shaft 68 is arranged so as to project into the valve chamber 56, and a spring holder 78 is fixed to the outer peripheral portion of the shaft 68. The outer peripheral portion of the spring holder 78 can come into contact with the bottom portion of the valve chamber 56. This spring holder 78 and the seat surface 6 of the seat valve 62
A return spring 80 is arranged between the outer periphery of 2A. Therefore, the return spring 80 constantly urges the shaft 68 in the direction of arrow A. When the spring holder 78 is in contact with the bottom of the valve chamber 56 under the biasing force of the return spring 80, the block 7
0 and the guide member 52, a predetermined air gap (Δ
G) is formed. Further, in this state, the spherical seal portion 68A at the other end of the shaft 68 is in an open state with being separated from the seat surface 62A of the seat valve 62. Then, from this open state, the coil 76 is energized, the block 70 is moved in the direction opposite to the arrow A direction in FIG.

Next, a method of manufacturing the spherical seal portion 68A of the shaft 68 will be described.

First, as shown in FIG. 1 (A), a concave portion 84 is previously formed in the axial center portion of the tip end portion of the raw material 82 which is a cylindrical solid shaft. Process 1 "
Equivalent). The recess 84 may be formed by upsetting or machining. Next, as shown in FIG. 1B, the material 82 is fixed to the die 86, and the punch 88 is applied to the tip of the material 82. The punch 88 is formed with a hemispherical recess 90. The steps up to this point are steps before cold forging.

Next, as shown in FIG. 1C, the spherical surface is processed by cold forging (corresponding to the "second step" in claim 1). That is, punch 8 into die 8
By pressing to the 6 side, the peripheral portion 92 of the concave portion 84 of the material 82 is brought closer to the top side of the concave portion 90 of the punch 88. In addition, the direction of meat approaching at this time is indicated by an arrow. In this process, the diameter of the recessed portion 84 is reduced and finally the spherical shape is formed, and the surplus portion 94 is formed at the tangent portion between the punch 88 and the die 86.

Next, as shown in FIG. 1D, the excess thickness portion 94 generated during cold forging is cut off by turning (or press punching) (the "third step" in claim 2). Is equivalent to). As a result, the shaft 68 having the spherically shaped seal portion 68A is formed. Since the excess thickness portion 94 is formed and then cut off as described above, the shaft 68 does not have a non-contact portion with the mold.

Next, the operation and effect of this embodiment will be described. In the present embodiment, a recess 84 is formed in advance in the axial center of the end of the material 82 that is a solid shaft, and the peripheral portion 92 of the recess 84 of the material 82 is reduced by cold forging. Therefore, the peripheral portion 92 is the concave portion 90 of the punch 88.
The resistance to fleshing when flowing along the inner peripheral surface (spherical surface) of is reduced. Therefore, the thickness of the peripheral portion 92 of the concave portion 84 is sufficiently spread to the spherical top portion of the concave portion 90 of the punch 88. Therefore, the area of the meat per die is increased as compared with the case where the meat is brought close without forming the concave portion 84. In addition, in the cold forging, the excess thickness portion 94 is formed in the gap between the die 86 and the punch 88.
Since the restraint forming is performed until the occurrence of, the area of the meat per die at the tangent portion also increases. From these things, according to this embodiment, the range effective as a sealing surface can be expanded from S'of the related art to S.

Further, according to this embodiment, the peripheral portion 92 of the recess 84 is formed into a spherical shape by cold forging, and at this time, the meat flows in the direction substantially orthogonal to the die surface, so that the punch 88 is A sufficient molding surface pressure is applied from the inner peripheral surface (spherical surface) of the recess 90. Therefore, the required surface roughness of the seal surface of the seal portion 68A can be ensured.

Further, as the post-processing, since the excess thickness portion 94 of the tangential line portion which occurs during cold forging is simply removed by turning (or press punching), no high-cost additional processing is required and the processing cost is reduced. Cost reduction can be achieved.
By turning the extra thickness portion 94, not only the range of the sealing surface can be expanded, but also the shaft 6
Since there is no untouched part on the mold in 8
The guide length when moving in the axial direction can be increased.
Therefore, it is possible to ensure the predetermined performance of the front sub-solenoid valve 14 including the shaft 68 as a valve.

Further, the shaft 68 having the above effects
Is used as the valve element of the ABS front sub-solenoid valve 14, the seat surface 6 of the seat valve 62 is
The sealing property with 2A can be improved. Therefore,
The accuracy of ABS control can be improved. further,
Since the guide length can be increased, rattling at the time of operation can be prevented, and the seal surface position can be stabilized.

The valve provided with the shaft 68 molded by the above-described molding method is applicable to various actuator valves utilizing hydraulic pressure or pneumatic pressure, in addition to the above-mentioned ABS.

[0041]

As described above, the end face forming method for the shaft member according to the present invention as defined in claim 1 includes the first step of forming a concave portion in the axial center portion of the end portion of the material which is the solid shaft. , A second step of forming the end surface of the material into a spherical shape by reducing the circumference of the concave portion of the material by cold forging, so that the spherical shape can be obtained without performing additional processing at high cost. The required surface roughness of the sealing surface can be secured,
Moreover, it has an excellent effect that the effective sealing surface can be expanded.

In the end face forming method for a shaft member according to a second aspect of the present invention, after the second step in the first aspect of the present invention, a third step for cutting off excess material generated in the circumferential direction of the raw material is provided. Since the step (1) is performed, the required spherical contact portion can be secured, and the guide length becomes long, so that the predetermined performance as a valve can be secured, which is an excellent effect.

Further, the ABS according to the present invention according to claim 3
The solenoid valve for a vehicle is equipped with a shaft member having an end surface of a spherical shape formed by the method according to claim 1 or 2.
Since it is used as a valve body of a solenoid valve for a vehicle, it has an excellent effect that the sealing property of the solenoid valve can be improved, the operation can be stabilized, and the accuracy of ABS control can be improved.

[Brief description of the drawings]

FIG. 1 is a process drawing showing a process for molding a seal portion of a shaft.

FIG. 2 is a sectional view showing the structure of a front sub-solenoid valve including the shaft shown in FIG.

FIG. 3 is a schematic diagram showing a layout of an oil passage of an ABS equipped with the front sub-solenoid valve shown in FIG.

FIG. 4 is a process diagram showing a manufacturing process of a plunger according to a conventional example.

FIG. 5 is a process drawing showing a process for molding a seal portion of a shaft according to another conventional example.

[Explanation of symbols]

10 ABS Actuator 14 Front Sub Solenoid Valve (ABS Solenoid Valve) 68 Shaft (Solenoid Valve Disc) 82 Material 84 Recess 92 Peripheral 94 Extra Thickness

Claims (3)

[Claims] 1. A first step of forming a concave portion in an axial center portion of an end portion of a raw material which is a solid shaft, and cold forging to reduce the circumference of the concave portion of the raw material while end face of the raw material. And a second step of forming the above into a spherical shape, and an end face forming method for a shaft member. 2. The end face forming method for a shaft member according to claim 1, wherein after the second step, a third step of cutting off a surplus thickness generated in the circumferential direction of the material is performed. . 3. A shaft member having a spherical end surface formed by the method according to claim 1 or 2,
A solenoid valve for ABS, which is used as a valve body of a solenoid valve for S.