WO2006054587A1

WO2006054587A1 - Press-fitting member

Info

Publication number: WO2006054587A1
Application number: PCT/JP2005/021022
Authority: WO
Inventors: Yasunao Ono; Kazuhiko Hayashi; Masayasu Tajima; Akira Yokoyama; Haruhisa Sato
Original assignee: Tanaka Seimitsu Kogyo Co., Ltd.
Priority date: 2004-11-17
Filing date: 2005-11-16
Publication date: 2006-05-26

Abstract

A press-fitting member used for tightening it integrally with a press-fitted member by press-fitting. The press-fitting member is characterized in that a first tapered part is formed in a direction in which its diameter is increased more than the maximum diameter of the end face of a press-fit start side tip part, a second tapered part is formed in a direction in which its diameter is increased more than the maximum diameter of the first tapered part, and the taper angle of the second tapered part is formed smaller than the taper angle of the first tapered part. The press-fitting member can be press-fitted to the press-fitted member with a fitting hole with high productivity and high tightening force.

Description

Specification

Press-fit member

Technical field

TECHNICAL FIELD [0001] The present invention relates to a press-fitting member that is fastened by press-fitting, and more specifically, press-fitting that can be press-fitted with a high fastening force with high productivity to a press-fitted member having a fitting hole. The present invention relates to a press-fitting member having a feature in the shape of the outer diameter side of the front end of the press-fitting side of the member.

Background art

Conventionally, as a technique related to a press-fitting member, generally, a press-fitting start side tip portion of the press-fitting member is chamfered, and the press-fitting member having a fitting hole which is similarly chamfered is subjected to the press-fitting. The member is press-fitted and fitted.

Also known is that the outer peripheral surface of the bushing (press-fit member) is crowned, and press-fitting technology for press-fitting the press-fit member into the inner peripheral surface of the boss hole of the aluminum alloy rocker arm is known. (See Patent Document 1).

Furthermore, a chamfered portion that contacts the fixed position of the press-fitting member is provided at the fitting start side tip of the fitting hole of the press-fitted member, and the diameter is reduced from the smallest diameter portion of the chamfered portion toward the smallest diameter portion of the fitting hole. A press-fit structure that forms a tapered portion is known (see Patent Document 2). Patent Document 1: Japanese Utility Model Publication No. 3-42004

Patent Document 2: JP 2001-263363 A

Disclosure of the invention

Problems to be solved by the invention

[0003] The above-described conventionally known technique, for example, when chamfering is performed on a fitting hole of a press-fitting member or a press-fitting member, as the press-fitting proceeds from the minimum diameter portion to the maximum diameter portion of the chamfered portion of the press-fitting member. Therefore, a large press-fitting load is required at the joint between the chamfered part and the outer diameter part of the press-fitting member where the press-fitting allowance increases and the press-fitting allowance increases most. Since a large press-fit load becomes a large resistance for the press-fitted member and the press-fitted member, there is a concern that distortion may occur and deformation or destruction may occur. For example, a large press-fitting load can be reduced by reducing the chamfer angle of the press-fitting member. If it is narrowed, it is necessary to widen the chamfer width or increase the diameter of the end face of the press-fitting start side. Increasing the chamfer width reduces the surface area of the outer diameter surface with the largest diameter and lowers the fastening force. To increase the surface area of the outer diameter surface in order to improve the fastening force, there is a need to increase the size or length of the press-fit member, which is not a preferable improvement method. When trying to increase the end face diameter of the press-fit member, eccentricity is likely to occur during press-fitting into the fitting hole of the press-fit member, which may lead to poor product quality due to lower press-fit accuracy and lower fastening force. Although technology for crowning the outer diameter of the press-fit member is described, it is difficult to manage the manufacturing process because it is easy to cause eccentricity when the press-fit member and the press-fit member are fastened by press-fitting. (See Patent Document 1).

Although it describes improvements related to the chamfered shape of the fitting hole of the pressed-in member, it requires high-precision machining on the inner diameter surface, so it is difficult to ensure dimensional accuracy in mass production. This is disadvantageous (see Patent Document 2).

The present invention has been made to solve the drawbacks of the prior art.

Means for solving the problem

The present inventors diligently studied to solve the above problems.

As a result, it is used to integrally fasten the press-fitting member and the press-fitted member by press-fitting, and has a tapered surface having two different taper angles on the outer diameter side of the press-fitting start side end of the press-fitting member. The first taper portion is formed in a direction in which the diameter increases from the maximum diameter portion of the end surface of the press-fitting start side tip portion in the axial direction, and then the second taper portion is the first taper portion. The above-mentioned problem is caused by a press-fitting member that is formed in a direction that expands from the maximum diameter portion of the portion in the axial direction and that the taper angle of the second taper portion is narrower than the taper angle of the first taper portion. I found out that it could be solved all at once.

Further, (i) a convex curved surface portion is provided between the maximum diameter portion of the first taper portion and the minimum diameter portion of the second taper portion, and / or (mouth) of the second taper portion. A convex curved surface portion is provided between the maximum diameter portion and the outer diameter portion of the press-fitting member; or / and (c) the maximum diameter portion of the end surface and the minimum diameter portion of the first taper portion. Convex curved surface It has also been seen that the provision of the portion enables more suitable press-fitting between the press-fitting member and the press-fitted member.

Furthermore, it has also been found that a more preferable press-fitting can be achieved by a press-fitting member in which the taper angle of the second taper portion is 5 to 15 °. It has also been found that the taper angle of the second taper portion is 5 to 15 °, and that the taper angle of the first taper portion is 20 to 90 °, further preferable press-fitting can be achieved. It has also been found that the most preferable press-fitting can be achieved by a press-fitting member in which the taper angle of the second taper portion is 5 to 15 ° and the taper angle of the first taper portion is 20 to 40 °.

After obtaining the above-mentioned new knowledge, the present inventors have made various studies and completed the present invention.

Therefore, the present invention

(1) A taper surface used for integrally fastening a press-fitting member and a press-fitted member by press-fitting and having two different taper angles on the outer diameter side of the press-fitting start side tip portion of the press-fitting member. The first taper portion is formed in a direction that expands from the maximum diameter portion of the end surface of the press-fitting start side tip end in the axial direction, and then the second taper portion is the first taper portion. (1) The taper portion is formed in a direction extending from the maximum diameter portion to the axial direction, and the taper angle of the second taper portion is narrower than the taper angle of the first taper portion. Press-fit member,

(2) The press-fitting member according to (1), wherein a convex curved surface portion is provided between a maximum diameter portion of the first taper portion and a minimum diameter portion of the second taper portion,

(3) The convex curved surface portion is provided between the maximum diameter portion of the second taper portion and the outermost diameter portion of the press-fitting member, according to any one of (1) to (2), Press-fit member,

(4) The deviation or deviation of (1) to (3), wherein a convex curved surface portion is provided between the maximum diameter portion of the end face and the minimum diameter portion of the first taper portion. The press-fitting member according to

(5) The press-fitting member according to any one of (1) to (4), wherein a taper angle of the second taper portion is 5 to 15 °.

(6) The press-fitting member according to any one of (1) to (5), wherein a taper angle of the first taper portion is 20 to 90 °. (7) The taper angle of the first taper portion is 20 to 40 °, and the taper angle of the second taper portion is 5 to: 15 °, any one of (1) to (4) Press-fitting member as described in

(8) A press-fit product, wherein the press-fit member according to any one of (1) to (7) is integrally fastened to the press-fit member by press-fitting,

(9) The press-fit product according to (8), wherein the press-fit product is an aluminum alloy rocker arm,

(10) The aluminum alloy rocker arm according to (9), wherein the press-fitting member is a bush fitted into the inner peripheral surface of the boss hole of the rocker arm.

(11) The aluminum according to (9) to (: 10), wherein the press-fitting member is a roller shaft that is press-fitted into the inner peripheral surface of the roller shaft hole of the rocker arm. Alloy rocker arm.

About.

The invention's effect

[0006] The press-fitting member of the present invention can be press-fitted into the fitting hole of the press-fitted member with high productivity and high fastening force, and can suppress generation of galling during press-fitting into the fitting hole. It is possible to press fit with good press fitting accuracy.

Brief Description of Drawings

FIG. 1 is an axial sectional view of a press-fitting member according to an embodiment of the present invention.

2 is a partially enlarged view of a front end portion of a press-fitting start side of a press-fitting member surrounded by a circle shown in FIG.

FIG. 3 is a partially enlarged view of a front end portion of a press-fitting start side of a press-fitting member having a conventionally known chamfering.

FIG. 4 is an explanatory view showing the press-fitting allowance of FIG.

FIG. 5 is an explanatory view showing the press-fitting allowance of FIG.

FIG. 6 is a cross-sectional view showing an installation state of the press-fitting member and the press-fitting member immediately before press-fitting when the press-fitting member according to the present invention is press-fitted to the press-fitted member.

FIG. 7 is a sectional view showing a state when the press-fitting member according to the present invention is integrally fastened to the press-fitted member by press-fitting.

[Fig. 8] Press fitting with and without galling when press-fitting the press-fitting member to the press-fitted member Test results showing the relationship between cost and press-fit load.

[Fig. 9] Test results showing the relationship between the press-fitting allowance when the press-fitting member is press-fitted to the press-fitted member and the removal load after the press-fitting member is press-fitted to the press-fitted member.

[Fig. 10] Test results showing the influence of the press-fitting allowance and the second taper angle of the press-fitting member on the presence or absence of galling when the press-fitting member is press-fitted to the press-fitted member.

Explanation of symbols

lO -... Press-fit member

ll -... Press-fit start side tip

12 ··· Press-fit start side tip

13 '' First taper part

14 ... _2nd taper part

is · Outer surface

le- --convex surface

17

18

19 ··· Inner diameter chamfer

20

30 ··· Pressure start side tip

31 ··· Pressure start side tip

32 ... Chamfer

33 ··· Outer diameter surface

40 ··· Press-fit member

41 ··· Mating hole

42 ··· Chamfer

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described based on the examples shown in the accompanying drawings.

1 to 10 show an embodiment of the present invention, and FIG. 1 shows a pressure according to the embodiment of the present invention. It is an axial sectional view of an insertion member. FIG. 2 is a partially enlarged view of the front end portion of the press-fitting start side of the press-fitting member surrounded by a circle shown in FIG. FIG. 3 is a partially enlarged view of a front end portion of a press-fitting start side of a press-fitting member having a conventionally known chamfering. FIG. 4 is an explanatory view showing the press-fitting allowance of FIG. FIG. 5 is an explanatory view showing the press-fitting allowance of FIG. FIG. 6 is a cross-sectional view showing the installation state of the press-fitting member and the press-fitting member immediately before press-fitting when the press-fitting member according to the present invention is press-fitted to the press-fitted member. FIG. 7 is a sectional view showing a state when the press-fitting member according to the present invention is integrally fastened to the press-fitted member by press-fitting. Fig. 8 shows the test results showing the relationship between the presence or absence of galling and the press-fitting allowance and press-fitting load when press-fitting the press-fitted member to the press-fitted member. Fig. 9 shows the test results showing the relationship between the press-fitting allowance when the press-fitting member is press-fitted to the press-fitted member and the removal load after the press-fitting member is press-fitted to the press-fitted member. Fig. 10 shows the test results showing the influence of the press-fitting allowance and the second taper angle of the press-fitting member when the press-fitting member is press-fitted on the press-fitted member on the presence or absence of galling.

First, referring to FIG. 1, the press-fitting member 10 has, for example, a cylindrical shape having a hollow. The press-fitting start side tip surface 12 is a donut circle formed in a direction perpendicular to the axial direction. The outer diameter surface 15 is formed to have the same diameter from the press-fitting start side tip surface 12 through the press-fitting start side tip portion 11 through the press-fitting start side tip portion 11 over the entire length excluding both tip portions. The inner diameter surface 20 is formed to have the same diameter from the front end surface 12 on the press-fitting start side through the inner diameter chamfered portion 19 to the entire length excluding the double-sided chamfered portion in the axial direction.

A preferable shape of the press-fitting start side tip portion 11 will be described as an example with reference to FIG. 2 and FIG. 3 together.

FIG. 3 shows the shape of the press-fitting start side tip 30 of a conventionally known press-fitting member. The press-fitting start side tip 30 extends from the maximum diameter part of the press-fitting start tip 31 to the outer diameter 33 side. In addition, a chamfered portion 32 is provided in the direction of increasing the diameter relative to the axial direction.

FIG. 2 shows a preferred shape and shape of the press-fitting start side tip portion 11 of the press-fitting member of the present invention. The press-fitting start side tip portion 11 is a convex curved surface portion from the maximum diameter portion of the press-fitting start side tip surface 12. The first taper portion 13 is provided in the direction of increasing the diameter from the maximum diameter portion of the convex curved surface portion 17 to the outer diameter surface 15 side and in the axial direction. Further, a convex curved surface portion 16 is provided from the maximum diameter portion of the first taper portion 13, and the shaft from the maximum diameter portion of the convex curved surface portion 16 to the outer diameter surface 15 side is provided. The second taper portion 14 is provided so that the taper angle is narrower than the taper angle of the first taper portion 13 in the direction of increasing the diameter relative to the direction. Further, a convex curved surface portion 18 is provided from the maximum diameter portion of the second taper portion 14, and the maximum diameter portion of the convex curved surface portion 18 is provided so as to be connected to the outer diameter surface 15.

Incidentally, the taper angle means an angle formed by a pair of bus bars whose diameter increases toward the outer diameter surface side in a cross section of the press-fitting member passing through the central axis of the press-fitting member. That is, the taper angle is twice the angle at which the central axis and the taper intersect.

4 and 5 together, the press-fitting start side tip portion 11 of the present invention shown in FIG. 4 is compared with the press-fitting start side tip portion 30 of the conventionally known press-fitting member shown in FIG. Since the first taper portion 13 and the second taper portion 14 have different taper angles, the first taper portion 13 is first press-fitted from the press-fit start portion toward the maximum diameter portion. As the pressure increases, the press-fitting volume increases in the A area and the press-fitting load gradually increases. As the press-fitting load increases, the narrower angle than the taper angle of the first taper part 13 as shown in the B area. Therefore, the present invention is a press-fitting member having the same press-fitting allowance as compared with the case of the conventionally known chamfered part 32. The press-fitting accuracy when press-fitting can be increased. That is, even if the press-fitting allowance is increased from the conventionally known press-fitting member, the press-fitting can be performed without any trouble.

In the present invention, the first taper portion 13 and the Z taper portion 2 or the second taper portion 14 are in the outer diameter direction with respect to the axial direction that is not the case of a flat surface that forms a simple conical surface. It can be combined with a curved clawing shape.

As a means for forming the preferable press-fitting start tip 11, for example, a grindstone used at the time of outer peripheral grinding of the outer diameter surface 15 is formed into a shape corresponding to the press-fitting start tip 11 in the shape of the press-fitting start tip 11. By using the formed whetstone and forming the press-fitting start side tip 11 simultaneously with the peripheral grinding of the outer diameter surface 15 by using this whetstone, a preferable press-fitting start side tip 11 can be obtained with high productivity. In addition, the press-fitting start-side tip 11 can be obtained by turning using a general-purpose tool formed in the shape of the press-fitting start-side tip 11.

Next, referring also to FIG. 6, first, preferably, positioning is performed so that the central axis of the fitting hole 41 of the press-fit member 40 and the central axis of the press-fit member 10 are on the same axis, and then Face of fitting hole 41 The press-fitting member 10 and the press-fitting member 40 are installed so that a part of the press-fitting start side tip part 11 is put on the catch part 42. As is well known, the outer diameter of the press-fitting member is set to be increased by the press-fitting allowance with respect to the inner diameter of the fitting hole 41, so that at least a part of the tip 11 on the press-fitting start side of the press-fitting member 10 is press-fitted. It hangs on the chamfered portion 42 of the member 40. Referring also to FIG. 7, after the press-fitting member 10 and the press-fitted member 40 are installed as described above, the other end side of the press-fitting member 10 opposite to the front end surface 12 of the press-fitting member 10 is installed with a hydraulic press or the like. The press-fitting member 10 is advanced into the fitting hole 41 of the press-fitted member 40 in the order of the first taper part 13 → second taper part 14 → outer diameter surface 15 to the press-fitting completion position. The press-fitting member 10 is press-fitted to the press-fitted member 40.

Next, the superiority when the press-fitting member according to the present invention is integrally fastened to the press-fitted member by press-fitting will be described.

Referring to Figs. 8 and 9, the graph in Fig. 8 shows the test results showing the relationship between the presence or absence of galling and the press-fit allowance and press-fit load. In the case of the press-fitting member of the present invention, the outer diameter is 16 mm, the first taper angle is 30 °, the second taper angle is 10 °, and the known press-fitting member has an outer diameter of 16 _mm and a taper angle of ₃₀ °. It was. The graph in Fig. 9 shows the test results showing the relationship between the press-fit allowance and the unloading load. In the example of FIG. 9 using the press-fitting member of the present invention, the press-fitting member is a steel hollow cylindrical member, the outer diameter is 16 mm, the first taper angle is 30 °, and the second taper angle is 10 °. . The press-fitted member is an aluminum alloy forged member having a fitting hole, and the fitting hole is provided with a chamfer so that the outer diameter portion of the press-fitting member is accommodated. The press-fitting allowance is a difference formed between the outer diameter of the press-fitting member and the inner diameter of the fitting hole. The press-fitting load means a maximum load required when the press-fitting member is press-fitted to the press-fitted member. The extraction load means the maximum load generated when the press-fitting member is forcibly removed from the opposite side to the press-fitting direction in order to measure the fastening force between the press-fitted member and the press-fitted member. Note that the galling shown in the graph of FIG. 8 means that, for example, when the press-fitting member is press-fitted into the fitting hole of the press-fitted member, the cores of the press-fitting member and the press-fitted member are displaced without matching at the time of press-fitting. As a result, the vicinity of the inlet of the fitting hole is scraped off at the tip of the press-fitting member during press-fitting, or a part of the inner diameter surface of the press-fitted member is caused by friction generated during press-fitting. The press-fitting member is intermittently cut or waved on the inner diameter surface of the fitting hole. It represents a state where it is press-fitted. Therefore, press-fitting with caulking may result in a poor press-fitting state because there is a risk of deterioration in product quality due to a decrease in press-fitting accuracy and a reduction in fastening force.

As the graph in Fig. 8 shows, the press-fitting load increases proportionally as the press-fitting allowance increases. The press-fitting member of the present invention having the press-fitting start side tip of the present invention shown in FIG. 2 (◯ in FIG. 8), and a known press-fitting member having the hitherto known press-fitting start side tip shown in FIG. Both the garden in 8 and X) have a larger press-fitting load as the press-fitting allowance increases, and the tendency is similar.

However, in this example, galling was confirmed when the press-fitting allowance was larger than 70 μm at the conventionally known press-fitting start tip, whereas the press-fitting allowance was 130 at the press-fitting start tip of the present invention. Even if μ ΐη, no galling is observed. As shown in the graph of Fig. 9, the load increases as the press-in allowance increases. However, the increase in the extrude load decreases as the press-in allowance increases. The tip end on the start side can be press-fitted with increased press-fit allowance without galling. The large unloading load means that the fastening force is large. Therefore, by using the press-fitting member of the present invention, press-fitting with a fastening force higher than that of conventionally known press-fitting members is possible. 9 represents a press-fitting member of the present invention having a press-fitting start side tip portion of the present invention. ).

The graph in Fig. 10 shows the test results showing the effect of the press-fitting allowance and the second taper angle of the press-fitting member on whether or not the press-fitting member is press-fitted into the press-fitted member. As shown in Fig. 10, when the second taper angle is 5 ~: 15 °, galling does not occur regardless of the press-fitting allowance. The first taper angle is 60 ° and the second taper angle is 20-40. In the case of, galling does not occur if the press-fitting allowance is less than 100 z m, but galling may occur if it is greater than lOO x m. In addition, galling occurs when the second taper angle is less than 5 ° and the press-fitting allowance is 100 zm or more. Therefore, the preferred range of the second taper angle is 5 to: 15 °.

8 to 10 were performed under the following conditions.

<Press-fit member>

Material: ADC12 equivalent Manufacturing method: Ordinary die casting

Heat treatment: T5 treatment (JIS H0001)

<Press-fit member>

Material: SUJ2 steel

Heat treatment: quenching and tempering

1st taper angle: 30 ° in Figs. 8 and 9, all 60 'in Fig. 10

Dimensions: Outer diameter Φ 16mm

<Press-fit conditions>

Applied pressure = 20kN

Actual press-fitting speed = 35mm / s Industrial applicability

The press-fitting member of the present invention can be press-fitted with a high fastening force with high productivity into the fitting hole of the press-fitted member, and is useful as a component of various machines.

Claims

The scope of the claims

[1] A taper surface having two different taper angles is used on the outer diameter side of the press-fitting start side of the press-fitting member that is used to integrally fasten the press-fitting member and the press-fitted member by press fitting. The first taper portion is formed in a direction in which the diameter increases from the maximum diameter portion of the end surface of the press-fitting start side tip portion with respect to the axial direction, and the second taper portion is then formed in the first taper portion. (1) The taper portion is formed in a direction extending from the maximum diameter portion to the axial direction, and the taper angle of the second taper portion is narrower than the taper angle of the first taper portion. Press-fit member.

[2] The press-fitting member according to claim 1, wherein a convex curved surface portion is provided between a maximum diameter portion of the first taper portion and a minimum diameter portion of the second taper portion.

[3] Any one of claims 1 to 2, wherein a convex curved surface portion is provided between a maximum diameter portion of the second tapered portion and an outermost diameter portion of the press-fitting member. The press-fitting member according to crab.

[4] A convex curved surface portion is provided between the maximum diameter portion of the end face and the minimum diameter portion of the first taper portion, according to any one of claims 1 to 3. Press-fit material as described.

[5] The press-fitting member according to any one of [1] to [4], wherein a taper angle of the second taper portion is 5 to 15 degrees.

[6] The press-fitting member according to any one of [1] to [5], wherein a taper angle of the first taper portion is 20 to 90 °.

[7] The taper angle of the first taper portion is 20 to 40 °, and the taper angle of the second taper portion is 5 to 15 °. 5. The press-fitting member according to any one of items 4.

[8] A press-fit product, wherein the press-fit member according to any one of claims 1 to 7 is integrally fastened to the press-fit member by press-fitting.

[9] The press-fit product according to claim 8, wherein the press-fit product is an aluminum alloy rocker arm.

[10] The press-fitting member is a bush that is press-fitted into the inner peripheral surface of the boss hole of the rocker arm. The rocker arm made of aluminum alloy according to claim 9 characterized by the above-mentioned.

The aluminum alloy product according to any one of claims 9 to 10, wherein the press-fitting member is a single shaft that is press-fitted into an inner peripheral surface of a roller shaft hole of the rocker arm. Rocker arm.