JPS60217027A - Press fitting apparatus - Google Patents

Abstract

PURPOSE:To prevent a die and a die case from damages due to excessive pressure in an apparatus for forcing a bearing into a housing, by making a die case holder and a die forcing tool engage slidably a core bar and providing an overload absorbing mechanism additionally. CONSTITUTION:One bearing 1b is fitted onto a small diameter portion 10b of a core bar 10 and mounted on a shoulder 10a of the core bar. A housing 2 is fitted onto said portion 10b and supported by a holder 13. Then this holder 13 is located by an outer diameter ruler 17. Next, the other bearing 1a is fitted onto said portion 10b and placed on the housing 2. Then, pressure P is applied to the end face of a lid 21 to force the bearings 1a, 1b into the housing 2, while elastic bodies 14, 22 are compressed to absorb the pressure when the pressure becomes overload. By this constitution can be prevented a die and a die case from deformation and damage due to overload.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a press-fitting device, particularly a press-fitting device for press-fitting a pair of press-fitting pieces (for example, a bearing, a bearing metal, etc.) into a piece case (for example, a bearing housing) for precise fitting. The present invention relates to a press-fitting device for use.

[Prior art]

Figure 1 shows a bearing for opposing press-fit parts such as a drum assembly of a VTR.
High precision is required for assembly of the housing 2 and the housing 2. For example, with respect to the reference plane S.

The parallelism of both end surfaces U and ■ of the bearings 1a and 1b is 3 μm, respectively, and the deflection of the reference surface S with respect to the axis ■ is 2 μm.
It is.

Conventionally, assembly of this type of bearing has been carried out in three steps using a press-fitting jig as shown in FIGS. 2 and 3.

First, in the first step, the housing 2, which has been made into a striped spring in advance, is heated. In the second step (Figure 2).

This heated housing is press-fitted into a core metal base 3 which is a fitting device.
The bearing 1a is hot press-fitted with the bushing 4 by applying a pressure P and using the core bar 3a as a guide. In the third step (FIG. 3), the housing 2 is replaced and the lower bearing 1b is press-fitted.

However, in such a conventional press-fitting device, even if the pressurizing force P becomes excessive, the resulting overload cannot be absorbed, so there is a risk that the bearing or the housing may be deformed. Furthermore, "gauling" occurs during press-fitting, which tends to impair bearing quality.

[Purpose of the invention]

The present invention was made to solve these conventional drawbacks, and aims to provide a press-fitting device that does not cause deformation or damage to the piece or piece case even if the pressurizing force becomes excessive. The purpose is

〔Example〕

FIG. 4 shows an embodiment of this invention. In the figure, 10
is a core metal, which is erected on a core metal mounting base 11 and fixed immovably with bolts 12. The core metal 10 has a small diameter portion 1 with the stepped portion 10a as a boundary.
0b and a large diameter portion 10c, and is formed such that the stepped portion 10a receives bearings 1a and 1b as pieces that are inserted in a sliding state from the tip of the small diameter portion. , 13 is a holder for the housing 2 as a piece case, which is slidably engaged with the large diameter portion 10c of the core metal 10 to hold the housing 2.
For example, it is disposed so as to be supported on its reference surface S, and is supported in a floating manner along the core shaft by being elastically supported via a spring 14.

15 is an upper limit stopper screwed into the side of the holder 13;
It fits into an axial long groove 16 provided in the core metal 10.

Reference numeral 17 denotes a ruler for regulating the outer diameter of the housing 2, which is formed into a ring shape and is fitted onto the end face of the holder 13 to align the center axes of the housing 2 supported by the end of the holder and the core metal 10. It has an effect. Reference numeral 18 denotes a press-fitting bush as a piece press-fitting tool, which has a through hole 18a for insertion into the small diameter portion 10b of the core metal 10. Reference numeral 19 denotes a press-fit overload absorption mechanism that elastically supports the press-fit bushing 18 in a floating manner, and includes a cylindrical case 20 into which the bush 18 is slidably inserted and attached to one end surface, and the other parts of the case 20. It is composed of a lid 21 screwed onto the end side and a spring 22 interposed between the lid 21 and the bush 18. Reference numeral 23 denotes a ventilation hole bored in the side surface of the case 20. Each of the parts constituting the above-mentioned press-fitting device is configured such that when the bearings 1a, 1b and the housing 2 are set as shown in the figure, the parallelism of both end faces U of the bearing, It goes without saying that the reference surface S is formed in such a manner that the deflection of the reference surface S with respect to 113 can be maintained at a standard value.

Next, the effect will be explained.

First, one side of the bearing, for example 1b, is inserted into the small diameter portion 10b of the metal core 10 and placed on the stepped portion 10a of the metal core. Then, the housing 2 is inserted and supported by the holder 13. At this time, this holder 13 is positioned using an outer diameter ruler 17. Further, another bearing, for example 1a, is placed on the housing 2 through it. After setting in this way, the bushing 18 is inserted into the tip of the core bar 10 (see FIG. 4). In this state, if a pressurizing force P is applied to the end face of the lid 21 using an appropriate pressurizing means, such as a press device, both the bearings 1a and 1b can be press-fitted into the housing 2 at the same time in one step.

During this press-fitting, even if the "fitting tolerance" between the bearings 1a, 1b and the housing 2 is larger than the specified value, conventionally they are forcibly press-fitted, and as a result, there is a risk of overloading and deforming the bearings themselves. However, according to this embodiment, the overload is absorbed as compressive energy by the elastic body 14, 22, so that the bearing is not forced into the seat to a specified depth.

Moreover, the bearing and the housing are well aligned by the holder 13 and the outer diameter ruler 17, and galling due to eccentric press fitting is less likely to occur.

FIG. 5 shows another embodiment, which differs from the above embodiment in that the press-fit overload absorbing mechanism 30 has an air spring structure. That is, in Figure 1, 31 is a sliding plate airtightly screwed onto the tip of the small diameter portion 10b of the core metal 10, and 32 is a sealing member, which seals air into the case 20 through the filling port 33. The pressure is adjusted by a regulating valve 34 to obtain an appropriate air spring force.

Only one of the piece case holder 13 and the piece press-fitting tool 18 in each of the above embodiments may be slidably engaged with the core bar 10, and a press-fitting overload absorption mechanism may be attached to this. good.

In addition, although the above-mentioned embodiment described the case of cold press-fitting, it is also possible to use hot press-fitting as necessary. Also, of course,
The present invention is not limited to press-fitting the bearing and the housing.

〔Effect of the invention〕

As described above, according to the present invention, deformation or damage to the press-fitted body can be effectively prevented by absorbing overload during press-fitting. It also improves press-fitting accuracy.

It can also prevent the "galling" phenomenon.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a workpiece in a press-fitting state, and FIG. 2 is a sectional view of a first press-fitting step using a conventional press-fitting device. FIG. 3 is a sectional view of the second press-fitting step, FIG. 4 is a sectional view of one embodiment of the present invention, and FIG. 5 is a sectional view of a main part of another embodiment. 1a, 1b...... Top (bear link) 2.
...... Top case (housing) 3a,
10...Core 13...Holder 18...(piece press-fit) Bushing 19.30...
・・・・・・Press-fitting overload absorption mechanism Fig. 1 Fig. 2 Fig. 3

Claims (1)

[Claims] In an example of a press-fitting device that press-fits a piece into a piece case using a cored metal as a guide, at least one of a piece case holder and a piece press-fitting tool is slidably engaged with the cored metal, and at the same time, the piece is press-fitted to the cored metal. A press-fitting device characterized by being equipped with a load absorption mechanism.