JPS63300831A - Bearing press fit method for base plate - Google Patents

Abstract

PURPOSE:To promote the improvement of a bearing for its internal diameter accuracy, out of roundness and horizontal and vertical degree by using one set of device forcing a pressing body to be press fitted while being supported to the guide part of a sizing bar, when the bearing is forced to be press fitted, and preventing the bar from its rotary deflection by the pressing body when the bearing performs its sizing work. CONSTITUTION:Inserting a guide part 8 of a sizing bar 6 into an oil-contained bearing 5 and placing it on a bearing mounting part 3, when a pressing body 4 is lowered adapting its point end to an upper surface of the bearing 5, the bar 6 is integrally connected with the pressing body 4 by inserting the point end part of the guide part 8 into a hollow part 9. Next the pressing body 4, when it is lowered while rotating the bar 6, is guided by the guide part 8, rotating in the central hollow part 9, vertically lowering with no deflection of a core and advancing the bearing 5 being forced to be press fitted to the bearing mounting part 3. As the result, a clearance between the bearing 5 and the guide part 8 is eliminated, and the bearing 5 is forced being press fitted horizontally with no tilting. Thereafter, the rotating bar 6 is lifted, and when its large contour machining part 10 is advanced being inserted into the bearing 5, the bearing, compressively machining its internal peripheral surface, is shaped straightening into a specified finishing size.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a pace plate bearing press-fitting method for press-fitting a bearing that supports a rotating shaft such as a motor into a bearing mounting portion of a base plate to adjust the inner diameter dimension of the bearing. It is something.

(Prior art) In general, in the disk drive unit of a floppy disk or compact disk, the rotating shaft of the motor needs to be supported by the bearing of the base plate with high precision in order to read the signal of the rotating disk using a laser beam. Strict dimensional tolerances, roundness, and horizontal/vertical accuracy are required.

As shown in Fig. 6, the conventional press-fitting method involves molding a ring-shaped bearing mounting part 3 into the hole 2 of the dowel plate.
The formed product is set in a press-fitting machine, and the pressing body is lowered from above to press-fit the bearing 3 as shown in FIG.

At this time.

Since the inner diameter of the bearing mounting portion 3 is smaller than the outer diameter of the bearing 3, the left side of the bearing receives compressive stress and its inner diameter is reduced, resulting in an inner diameter smaller than the finished dimension.

Remove this sickle and base plate from the press-fitting machine, set it on the sizing machine, and compress the inner periphery of the bearing 3 by inserting the sizing bar B from above while rotating, as shown in Figure 8. The inner diameter is adjusted to the finished size.

However, in the conventional method, bearings! The press-fitting and sizing of the inner diameter are performed in separate processes, resulting in poor workability and the need for two devices, which increases costs.

Also, if the axis of the pressing body l of the press-fitting machine is even slightly misaligned,
As shown in FIG. 9, the bearing S is press-fitted into the bearing mounting part 3 at an angle, and even if the sizing process is carried out in this state, the bearing S cannot be leveled, and the sizing bar is not correct. - If the shaft center of B is misaligned and rotates while wobbling, roundness and perpendicularity cannot be obtained, which causes product defects.

(Problems to be Solved by the Invention) As a result of research conducted in view of such conventional problems, the present invention improves workability by performing bearing press-fitting and inner diameter sizing processing in one device. The present invention provides a base plate bearing press-fitting method that improves product yield by increasing the dimensional accuracy, roundness, and horizontal/verticality of the bearing inner diameter.

(Means for Solving the Problems) The present invention provides a bearing mounted on a ring-shaped bearing mounting portion provided on a base plate, and a guide portion on the tip side of a sizing bar is directed downwardly between the bearing mounting portion and the bearing. Penetrate the bearing further upwards, then lower the pressing body above the bearing to bring it into contact with the upper part of the bearing, and insert the tip of the guide part into the recess formed at the tip of the pressing body to press it. While supporting the body and the bearing at the same time, the pressing body is lowered to press fit the bearing into the bearing mounting part, and then the sizing bar is rotated and raised to form a machined part with a larger outer diameter at the bottom of the guide part. This is characterized by sizing the inner diameter of the bearing.

(for production) The present invention will be explained below with reference to the drawings.

First, as shown in FIG. 1, the base plate is placed on the support stand 7 and positioned. At this time.

Since the guide portion on the tip side of the sizing bar 6, which is attached to the support base 7 so as to be movable up and down, protrudes upward, this guide portion S passes through the ring-shaped bearing mounting portion 3 molded on the base plate. Set it as follows.

The sizing bar 6 has a tip side formed with an outer diameter D' smaller than the finished inner diameter, a lower side formed with the same outer diameter as the finished inner diameter, and is supported by the tip of a lower cylinder (not shown) so as to be able to move up and down. In addition, it is connected to a motor and supported rotatably.

Next, a sizing bar 6 protrudes upward from the bearing mounting part 3.
An oil-impregnated bearing (O-IRES METAL) is used in the guide part g! r and place it on the bearing support part 3.

Next, as shown in FIG. 2, the pressing body q is lowered by an upper cylinder (not shown), and its tip abuts against the upper surface of the bearing 3. The tip of the pressing body.

Since a recess q is formed inside and is a cylindrical button, the protruding tip portion of the guide portion S of the sizing bar 6 is inserted into the recess, and the sizing bar B and the pressing body g are integrally connected.

Next, when the pressing body is lowered by the upper cylinder while rotating the sizing plate, the pressing body is guided by the rotating guide part S in the recessed part in the center, so that it will not be misaligned. It descends vertically and press-fits the left bearing into the bearing mounting part 3. At this time, the bearing 5 is also guided by the rotating guide part, so there is no misalignment, and oil seeps out due to friction, so there is almost no gap between the smooth and the bearing S. is press-fitted horizontally without tilting.

After that, as shown in Fig. 4, when the rotating sizing wheel B is raised and the large-diameter machined part 10 is inserted into the bearing S, the inner circumference inside the bearing S, whose inner diameter has been reduced, is The surface is compressed and sizing is performed to obtain the specified finished dimensions.

At this time, the guide part g at the tip of the sizing bar B is inserted into the concave part D of the pressing body G and rotates while being supported, so rotational runout is prevented, and the inner diameter of the sized bearing S is made with dimensional accuracy. It has a good shape and can be finished perfectly round.

And up to sr5! , the sizing bar moves down and stops at a predetermined position at the same time as the %under operates and the pressing body moves up. Next, when the base plate is removed, the sizing bar 6 rises again and stops when the guide portion g protrudes above the support base 7, returning to the initial state.

In the above description, the method of press-fitting the bearing 3 while rotating the sizing bar 6 has been described, but it is also possible to stop the sizing bar B during press-fitting and rotate it only when performing the sizing process.

(Example) A sintered oil-impregnated bearing S having an outer diameter of 8.002 mmψ and an inner diameter of 3.995 mmψ is placed on the bearing mounting portion 3 of the base plate. Next, while rotating the sizing bar 6, the pressing member is lowered, and the bearing 5 with a diameter of 7.982 cm ψ is press-fitted into the bearing mounting portion 3. At this time, the outer diameter of the guide part g of the sizing bar B is 3.985 mmψ, and the processed part g of the lower part is 3.99 mm.
A one with a diameter of 7 mmψ was used. Further, the inner diameter of the recess D of the pressing member G was 3.998 mmψ.

Next, the sizing bar 6 was raised and the processing section /θ was rotated to perform sizing processing on the inner circumference of the bearing 3.

The finished inner diameter of the bearing S installed in this way is 3.99
With a diameter of 65 mm, it was possible to finish within the specified tolerances, and the horizontal and vertical degrees were also within the specified limits.

(Effects of the Invention) As explained above, according to the base plate bearing press-fitting method according to the present invention, press-fitting and sizing can be performed with one device, and the workability is excellent. The bearing is press-fitted while being supported by the guide part of the sizing bar, and the pressing body prevents rotational vibration of the sizing bar during the sizing process, so the press-fitted bearing has high inner diameter dimensional accuracy and roundness, and the product has high horizontal and vertical degrees. The yield can be improved.

[Brief explanation of drawings]

Figures 1 to 5 are cross-sectional views showing the method of the present invention according to the sequential steps, Figures 61 to 9 show the conventional method, Figure 6 is a cross-sectional view showing the state during press-fitting, and Figure 7. 8 is a sectional view showing a state in which sizing is being performed, and FIG. 7 is a sectional view of a bearing that has been eccentrically sized.

Claims (1)

[Claims] Place the bearing on the ring-shaped bearing mounting part provided on the base plate, pass the guide part on the tip side of the sizing bar through the bearing mounting part and the bearing from below to above, and then press the bearing from above. The body is lowered to contact the upper part of the bearing, and the tip of the guide part is inserted into the recess formed at the tip of the pressing body to support the pressing body and the bearing at the same time, and the pressing body is lowered to mount the bearing. A base plate bearing characterized in that the inner diameter of the bearing is sized with a machined part having a larger outer diameter formed at the lower part of the guide part by being press-fitted into the guide part and then raised while rotating a sizing bar. Press-fitting method.