JPH0594515U - Press fit assembly - Google Patents

Abstract

(57) [Summary] [Purpose] The main object of the present invention is to provide a press-fitting assembly that has a small variation in press-fitting load and that can have a relatively large interference and machining tolerance. A press-fitting assembly having a press-fitted member 39 having a hole with a circular cross-section, and a cylindrical press-fitted member 50 press-fitted into the hole of the press-fitted member 39, wherein the outer peripheral surface of the press-fitted member 50 is:
A corrugated press-fitting portion 54 is provided. The waveform press-fitting portion 54 is
A plurality of convex portions 52 having a mountain diameter D2 larger than the inner diameter D1 of the hole of the press-fitted material 39 and a plurality of concave portions 53 having a valley diameter D3 smaller than the inner diameter D1 of the hole are alternately formed in the axial direction. On the front surface side of the convex portion 52 of the corrugated press-fitting portion 54 in the press-fitting direction, tapered press-fitting guide surfaces 55, 56 are provided that are gently inclined so that the outer diameter gradually increases from the front to the rear.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a press-fitting assembly having a press-fitting part press-fitted into a hole of a press-fitted material.

[0002]

[Prior Art]

 When a columnar press-fitted part is press-fitted into a press-fitted material having a hole with a circular cross-section, as shown in Fig. 6, the radial deformation of the press-fitted part a and the press-fitted material b causes the position depending on the axial direction. Press-fit load is generated. In this case, the tightening margin Δd is half the difference between the outer diameter of the press-fitted part a and the inner diameter of the press-fitted material b. As shown in FIG. 7, the characteristics of the press-fitting load are such that the press-fitting load rapidly increases with an increase in the press-fitting stroke.

[0003]

[Problems to be solved by the device]

 In the press-fitting assembly described above, if the press-fitting load is high, not only a high-output hydraulic press device is required for press-fitting work, but also the press-fitting part a and the press-fitted material b are, for example, magnetic materials. If the material is relatively soft, foreign matter such as shavings and “burrs” generated by press fitting may enter the inside of the press fitting assembly, and the function of the press fitting assembly may be impaired. In addition, if the press-fitting load is too high, the press-fitting part a or the press-fitted material b may be deformed and cannot be used.

For this reason, it is necessary to strictly control the fitting tolerance and surface roughness of the press-fitted part a and the press-fitted material b within a fairly narrow range, but the one having the press-fitting load characteristics as in the conventional example described above. Even within the range of general press-fitting tolerance (for example, H7-p7 conforming to JIS B0401), the press-fitting load fluctuates greatly depending on the maximum value and the minimum value of the tightening margin Δd. To reduce the variation of the press-fit load, the fitting tolerance should be narrowed. However, narrowing the fitting tolerance compared with the conventional method leads to a large increase in processing cost, etc., making it unsuitable for practical use.

Therefore, an object of the present invention is to provide a press-fitting assembly in which a change in the press-fitting load due to variations in tightening margin is small, a stable press-fitting load can be obtained, and a machining tolerance can be relatively large. To provide.

[0006]

[Means for Solving the Problems]

 The present invention developed to achieve the above object is a press-fitting assembly having a press-fitted material having a hole having a circular cross section and a press-fitted part that is press-fitted into the hole of the press-fitted material. The outer peripheral surface of or the inner peripheral surface of the material to be press-fitted is provided with a corrugated press-fitting portion in which a plurality of convex portions and concave portions that cause plastic deformation by press-fitting are alternately formed in the press-fitting direction. is there.

[0007]

[Action]

 When the press-fitting of the press-fitting part into the hole of the press-fitting material is started during the assembling work of the press-fitting part and the press-fitting material, the first convex portion located at the forefront part of the corrugated press-fitting part becomes a hole. Since the plastic deformation occurs when entering, the press-fitting load increases according to the press-fitting stroke, and then the press-fitting load stops increasing once. The same behavior is repeated when the second and subsequent protrusions enter the hole, and the total press-fit load gradually rises according to the number of protrusions inserted. For this reason, the rise of the press-fitting load with the increase of the press-fitting stroke becomes relatively gentle and stable, and the change of the press-fitting load due to the variation of the interference is small.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. An anti-skid device (ABS) 10 for an automobile, a part of which is shown in FIG. 3, includes a normal open valve 11 and a normally closed valve 12 as an example of a solenoid valve device. The master cylinder 13 is driven by the brake pedal 14. The first connection port 20 of the normal open valve 11 is connected to the master cylinder 13 via a pipe line 22.

The second connection port 21 of the normally open valve 11 is connected to a wheel cylinder 25 via a pipe line 23. The second connection port 21 is connected to the second connection port 27 of the normally closed valve 12 via a pipe line 26. The first connection port 28 of the normally closed valve 12 is connected to the reservoir 30 via a conduit 29. A pump 31 for pumping the brake fluid and a check valve 32 for preventing backflow are provided between the reservoir 30 and the master cylinder 13.

As shown in FIG. 2, the normally open valve 11 includes a solenoid 36 built in a housing 35. The metal housing 35 in the illustrated example includes an outer cylinder 37, an end member 38 fixed to one end of the outer cylinder 37, and a press-fitted member 39 fixed to the other end of the outer cylinder 37. A cap 40 is fixed to the end member 38. A hole 41 having a circular cross section along the axial direction is formed in the central portion of the press-fitted material 39.

An annular groove 47 for accommodating the O ring 45 and the backup ring 46 is provided on the outer peripheral portion of the press-fitted material 39. An inner cylinder 48 is fixed to the press-fitted member 39 and the cap 40. A cylindrical press-fitting component (core) 50 having an axial through hole 49 is fixed inside the inner cylinder 48 and the hole 41. A valve chamber 51 is provided on the lower end side of the press-fitting part 50. The press-fitting part 50 is made of a magnetic material.

As shown in FIG. 1, in the press-fitting component 50, a plurality of protrusions 52 and holes 41 having a mountain diameter D2 larger than the inner diameter D1 of the hole 41 of the material 39 to be press-fitted in a cross section along the axial direction. A corrugated press-fitting portion 54 is provided in which a plurality of concave portions 53 having a valley diameter D3 smaller than the inner diameter D1 are alternately formed in the axial direction. The protruding height of the convex portion 52 is, for example, about 0.1 or about 0.3 mm. The tip surface of the convex portion 52 has a flat shape over an appropriate length (for example, about 0.2 mm) in the axial direction of the press-fit component 50.

In the corrugated press-fitting portion 54, the first convex portion 52 located at the frontmost portion in the press-fitting direction is gently inclined at an angle θ 1 so that the outer diameter gradually increases from the front to the rear. A first press-fitting guide surface 55 having a tapered shape is provided. A second press-fitting guide surface 56 is provided on the front side of the second and subsequent convex portions 52, which is inclined at an angle .theta.2 larger than that of the press-fitting guide surface 55. An example of θ1 is 15 ° and an example of θ2 is 30 °, but these values are appropriately changed as necessary.

The back surface 57 of the convex portion 52 is processed into a concave surface having a radius of curvature R. An example of the radius of curvature R is 0.2 to 0.3 mm. At the opening edge of the hole 41 of the material 39 to be press-fitted, an inclined surface 58 which is processed to have an angle equivalent to the inclination angle θ1 of the press-fitting guide surface 55 is provided.

When the press-fitting of the press-fitting member 50 into the hole 41 of the press-fitted material 39 is started at the time of assembling the press-fitting assembly including the press-fitted material 39 and the press-fitting part 50, the first press-fitting guide surface 55. When the first convex portion 52 continuing to enter the hole 41 enters the hole 41, the convex portion 52 is plastically deformed to increase the press-fitting load according to the press-fitting stroke, and then the increase of the press-fitting load is temporarily stopped. The same behavior is repeated when the second and subsequent convex portions 52 enter the hole 41, and the total sum of the press-fitting loads gradually increases according to the number of the convex portions 52 inserted. Therefore, there is a relationship between the press-fitting stroke and the press-fitting load as shown by the solid line A in FIG. 4, and the increase in the press-fitting load becomes slower than the conventional characteristic (shown by the chain double-dashed line B).

Further, as shown in FIG. 5, as compared with the conventional press-fitting tightening allowance (L2-L1) required to obtain a predetermined press-fitting load (P2-P1), the press-fitting tightening allowance of the present embodiment. (L4-L3) can be set within a very wide range. Therefore, in the case of this embodiment, the change in the press-fitting load due to the variation in the tightening margin is small. Therefore, the fitting tolerance and the surface roughness can be allowed in a relatively wide range.

Further, since the press-fitting load is not too high, foreign matters such as shavings and “burrs” are prevented from entering the inside of the hole 41 during press-fitting, and deformation due to the press-fitting load being too high is also avoided. To be done. The press-fitting load can be adjusted by appropriately selecting the number, shape or size of the convex portions 52 and the concave portions 53, the pitch, and the specific aspects of the inclination angles θ1 and θ2.

A cylindrical plunger 59 made of a magnetic material is housed inside the cap 40. The plunger 59 can move in the axial direction of the housing 35. The plunger 59 is urged in a direction away from the press-fitting component 50 (upward in the drawing) by an elastic force of a compression coil spring 60 provided between the plunger 59 and the press-fitting component 50. This plunger 59 is adapted to be attracted to the press-fitting component 50 side by the magnetic field generated when the solenoid 36 is excited by energization.

A rod 61 is fixed to the plunger 59. The rod 61 passes through a through hole 49 provided in the press-fitting component 50 and extends to the valve chamber 51 side. A valve body 63, which is a component of the main valve 62, is provided at the tip of the rod 61. The valve body 63 is made of a high hardness material such as a tempered steel ball. The valve body 63 is separated from the valve seat 73 below by the elastic force of the spring 60 when the solenoid 36 is not excited.

A valve seat member 65 is fixed to the lower end surface of the press-fitted member 39. The valve sheet member 65 is made of a heat-treated high hardness material. An annular groove 69 for accommodating the O-ring 68 is provided on the outer peripheral portion of the valve seat member 65. The valve sheet member 65 is provided with a main flow hole 70 and a lateral flow hole 71. An annular valve seat 73 is formed at the opening 72 of the main flow hole 70. The valve sheet 73 faces the valve body 63, and is in contact with the valve body 63 when the valve is closed. The main flow hole 70 communicates with the first connection port 20 via the orifice 74.

A filter 80 is provided inside the first connection port 20. The filter 80 is fixed to the valve seat member 65 by a retaining ring 81. The lateral flow hole 71 communicates with the lateral hole 82. The lateral hole 82 is connected to the second connection port 21. A filter 85 is provided in the lateral circulation hole 71.

Further, the valve seat member 65 is provided with a check valve flow hole 91 that constitutes the return check valve 90. A valve seat 92 and a valve chamber 93 are formed in the through hole 91. A check valve body 94 that contacts the valve seat 92 and a return spring 95 that urges the check valve body 94 in the direction of pressing the valve seat 92 are housed in the valve chamber 93.

The return spring 95 is provided between the filter 80 and the check valve body 94 in a compressed state. The check valve body 94 is designed to open against the elasticity of the return spring 95 when the pressure on the valve chamber 51 side becomes higher than the pressure on the check valve chamber 93.

The normal open valve 11 having the above structure is fitted into the hole 97 provided in the valve unit base 96, so that the main flow passage 70 communicates with the pipe line 22 through the first connection port 20. At the same time, the lateral flow hole 71 communicates with the conduit 23 via the second connection port 21.

The normally closed valve 12 shown in FIG. 3 includes a solenoid 121 built in a housing 120 and a plunger 122 made of a magnetic material. Below the plunger 122 in the drawing, there is a valve chamber 123. The plunger 122 is urged by the elastic force of the compression coil spring 125 in the direction of pressing the valve body 126 against the valve seat 127. The valve chamber 123 communicates with the main flow hole 130 when the valve body 126 opens. Further, the lateral circulation hole 131 communicates with the valve chamber 123. The mainstream communication hole 130 communicates with the first connection port 28. A filter 133 is provided inside the first connection port 28. The lateral circulation hole 131 communicates with the second connection port 27. A filter 135 is also provided in the lateral circulation hole 131.

Next, the operation of the anti-skid device 10 having the above structure will be described. When the brake pedal 14 is depressed, the brake fluid pressurized by the master cylinder 13 flows through the pipe line 22 toward the normally open valve 11. Therefore, the break liquid enters the main flow hole 70 through the orifice 74, makes a U-turn in the valve chamber 51 and enters the lateral flow hole 71, and also passes through the filter 85 to the pipe line 23 to the wheel cylinder 25. Flows. In this case, the check valve 90 remains closed because the pressure in the master cylinder 13 is higher than the pressure in the wheel cylinder 25.

When the foot is released from the brake pedal 14, the master cylinder 13 returns to its original position, so that the brake fluid in the wheel cylinder 25 flows toward the normally open valve 11. That is, the brake fluid flows from the conduit 23 through the filter 85 into the valve chamber 51, makes a U-turn, enters the check valve flow hole 91, pushes the check valve body 94 open, and flows toward the conduit 22. Part of the brake fluid passes through the main valve 62 and the main circulation hole 70 in the open state, the pipe line 22, and returns to the master cylinder 13.

If the wheels tend to slip with respect to the road surface when the brake pedal 14 is depressed, the opening / closing control of the normal open valve 11 and the normal close valve 12 is performed by a well-known controller. That is, at the beginning of the slip, the solenoid 36 of the normally open valve 11 is energized to close the valve body 63 of the main valve 62. The normally closed valve 12 remains closed. With this holding mode, the pressure of the wheel cylinder 25 is held.

If the slip is not eliminated in the holding mode, the solenoid 121 of the normally closed valve 12 is energized and the valve body 126 is opened. The normal open valve 11 is maintained in the closed state. By doing so, the brake fluid in the wheel cylinder 25 flows to the reservoir 30 side, the pressure in the wheel cylinder 25 is released, and the locked state of the wheels is released.

After that, the power supply to the normally open valve 11 and the normally closed valve 12 is cut off, the normally closed valve 12 is closed again, and the normally open valve 11 is opened. Therefore, if the brake pedal 14 is continuously depressed, the hydraulic pressure of the master cylinder 13 is applied to the wheel cylinder 25 again.

As described above, every time the normally open valve 11 is driven in the valve closing direction, the magnetic attraction force, which is the thrust load by the plunger 59, acts repeatedly on the press-fitting component 50. However, since the press-fitting component 50 is securely fixed to the press-fitted member 39 at the corrugated press-fitting portion 54 with a predetermined press-fitting load, there is no problem that the press-fitting component 50 moves due to the thrust load.

The corrugated press-fitting portion 54 may be provided on the inner peripheral surface of the hole 41, contrary to the above embodiment. In that case, the outer peripheral portion of the press-fit component 50 may be a straight cylindrical smooth surface. Further, the plurality of protrusions 52 and the plurality of recesses 53 may be independent from each other in the axial direction of the press-fit component 50, or may be continuous in a spiral shape such as a ridge and a valley of a screw. It may be. Further, the present invention can be similarly applied to a press-fitting assembly of various devices other than the above solenoid valve.

[0033]

[Effect of the device]

 According to the present invention, since the change of the press-fitting load due to the variation of the press-fitting tightening margin is small and the stable press-fitting load is obtained, the reliability of the press-fitting assembly is improved. Further, since the machining tolerance can be made relatively large, the machining cost can be reduced.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a part of a press-fitting assembly showing an embodiment of the present invention.

2 is a longitudinal cross-sectional view of a solenoid valve that uses the press-fitting assembly shown in FIG.

FIG. 3 is a diagram showing a hydraulic system of an apparatus including the solenoid valve shown in FIG.

FIG. 4 is a diagram showing a relationship between a press-fitting stroke and a press-fitting load of the press-fitting assembly shown in FIG.

5 is a diagram showing the relationship between the interference and the press-fit load of the press-fit assembly shown in FIG.

FIG. 6 is a view conceptually showing a press-fit portion of a conventional press-fit assembly.

FIG. 7 is a diagram showing a relationship between a press-fitting stroke and a press-fitting load of a conventional press-fitting assembly.

[Explanation of symbols]

39 ... Press-fitted material, 41 ... Hole, 50 ... Press-fitted part, 52 ... Convex part, 53 ... Recessed part, 54 ... Corrugated press-fitted part, 55, 56 ... Press-fitted guide surface.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Koji Yusa 4056 Sakuradai, Nakatsu, Aikawa-cho, Aiko-gun, Kanagawa Prefecture

Claims (2)

[Scope of utility model registration request] 1. A press-fitting assembly having a press-fitted material having a hole of circular cross section and a press-fitted part press-fitted into the hole of the press-fitted material, the outer peripheral surface of the press-fitted part or the press-fitted material. A press-fitting assembly comprising an inner peripheral surface provided with a corrugated press-fitting portion in which a plurality of convex portions and concave portions that are plastically deformed by press-fitting are alternately formed in the press-fitting direction. 2. A taper-shaped press-fitting guide surface that is gently inclined so that the outer diameter gradually increases from the front to the rear on the front surface side of the convex portion of the corrugated press-fitting portion in the press-fitting direction. 1. The press-fitting assembly described in 1.