JPH0739062B2 - Press-fitting method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a pressurizing force according to a processing condition of a work in fitting and assembling processes of a precision disk and other precision parts such as a turntable of a compact disc player by pressing. The present invention relates to a press-fitting method and a press-fitting device that enable press-fitting without misalignment of the axis.

<Prior Art> Conventionally, for example, a turntable of a compact disc player and a motor shaft can be fitted with each other by using a press-fitting device as shown in FIG. That is, the work support jig 62 is fixed to the work table 61b of the press 61, and the motor 64 in which the turntel 63 is loosely fitted to the motor shaft 64a has its axis aligned with the central axis of the press head 61a of the press 61. As described above, the work support jig is supported by the chassis 65, and the pressure head 61a is lowered to move the turntable 63 to the motor shaft 64a.
It is pushed in and is tightly fitted.

<Problems to be Solved by the Invention> However, since the above-described conventional press-fitting device has a structure in which the lower end of the pressurizing head 61a directly presses the turntable 63, which is a workpiece, the unevenness of the sliding contact surface 61c of the pressurizing head 61a. There is a drawback that the pressing direction deviates from the center axis of the work due to rattling at the time of ascending and descending due to the above. That is, as shown in FIG. 7 (b), the turntable 63 and the motor shaft 64a, which are required to have a fitting accuracy on the order of micrometers, have their respective axes aligned with the central axis A of the pressure head 61a during press fitting. It is desirable that they are exactly the same, and the allowable range of misalignment of the shaft center is from the viewpoint of assembly accuracy.
It is required to be within 0.01 °. However, as shown in FIG. 7 (a), the actual deviation angle θ is affected by the accuracy of the press 61 and reaches several tens of times the permissible value due to the rattling. Bending and tilting occur, which causes surface wobbling and center wobbling of the compact disc during use, which significantly impairs player performance. Further, the above-mentioned conventional press-fitting device cannot adjust the press-fitting load to an appropriate range according to the processing conditions of the work,
Moreover, since it is not measured at the same time as the press-fitting load, it is difficult to obtain the optimum fitting.If the press-fitting load is less than the upper limit value, the fitting is too loose, causing the turntable 63 to idle when used, and the press-fitting load is If the upper limit value is exceeded, there is a drawback in that the fitting is too tight and the motor shaft 64a is bent or tilted to cause the above-mentioned surface wobbling or the like during use. In other words, no matter how the shaft diameter of the motor 64 and the press-fitting hole diameter of the turntable 63 are machined within the fitting accuracy, a defect will occur in the compact disc player as a product due to the above-mentioned drawbacks. Further, there is a drawback that the load cell used as the load detecting means of the press-fitting device is expensive.

Therefore, an object of the present invention is to provide a press-fitting method capable of press-fitting a work requiring high fitting accuracy within a proper pressurizing range within a proper pressing force range without displacement of a shaft core, and a press-fitting method used together with a press. It is to provide a simple and inexpensive press-fitting device.

<Means for Solving the Problems> In order to achieve the above object, in the press-fitting method of the present invention, the piston is movably arranged in the cylinder, and the spring is compressed so that the spring force can be adjusted between the piston and the cylinder. Then, a pressure transmission element that transmits the pressure from the cylinder to the piston via this spring is connected to the tip of the press head of the press,
A universal joint is connected to the pressure transmission element, and the pressure transmission element includes a lower limit pressing force detecting means for detecting a time point at which the piston begins to move relative to the cylinder against the spring, and the piston resists the spring. Equipped with upper limit pressure detection means for detecting the time of contact with the cylinder.
The work placed on the work table of the above press,
The pressurizing head pressurizes and presses through the universal joint and the pressure transmitting element, and an alarm is issued based on the detection signals from both the detecting means.

Further, the press-fitting device of the present invention is connected to the tip of the pressurizing head of the press, the piston is movably arranged in the cylinder, and the spring is compressed so that the spring force can be adjusted between the piston and the cylinder. Pressurizing force is transmitted from the cylinder to the piston through this spring, and the lower limit pressing force detecting means for detecting the time when the piston starts to move relative to the cylinder against the spring, and the piston against the spring and the cylinder Pressure transmission element having an upper limit pressure detection means for detecting the time point of contact with the pressure table, a universal joint connected to the pressure transmission element, and a work table of the press which are slidable coaxially with the center axis of the work. A press-fitting head supported by and connected to the universal joint,
An alarm unit is provided for issuing an alarm based on the detection signals from both the detection units.

<Operation> A worktable, for example, a turntable having a press-fitting hole and a motor shaft are mounted on the worktable of the press so that their central axes pass through the center of the universal joint and are parallel to the pressing direction of the pressing head. Place. Next, the pressure head is driven to press the work toward the work table via the pressure transmission element and the universal joint.

At this time, for example, the spring force of the pressure transmitting element is adjusted so that the piston starts to move relative to the cylinder under a desired lower limit pressure given in advance, and the piston and the cylinder body are respectively connected to the negative side wire of the external battery. By connecting to the + and + side conductors, a lower limit force detecting means for interrupting the current flowing through the conductors at a distance from the cylinder body of the spring is constructed. Also,
The amount of protrusion of the piston is adjusted so that the piston abuts the lower end surface of the cylinder, which is insulated from the cylinder body, against the spring under a desired upper limit pressurization given in advance, and the piston and the lower end surface of the cylinder are connected to the external battery. By connecting the negative side wire and the positive side wire, respectively, upper limit pressing force detecting means is formed in which a current starts flowing through the conductive wire when the piston contacts the cylinder. If, for example, a buzzer or a lamp is provided as an alarm means on the conductor, the alarm means is powered by an external battery when the pressure applied to the work is less than the lower limit pressure or greater than the upper limit pressure. Sound and light alarms.

On the other hand, since the pressing force is applied to the work through the universal joint, even if there is a misalignment between the axis of the pressure head and the axis of the work, the work will be forced in the oblique direction as in the past. Does not work.

<Examples> Hereinafter, the present invention will be described in detail with reference to illustrated examples.

FIG. 1 is a schematic view showing an embodiment of a press-fitting device used for carrying out the press-fitting method of the present invention, in which 1 is a press, 2 is a lower end of a press head 1a of the press 1, and a built-in spring is provided. The pressure transmitting element 3 for transmitting the pressing force through the universal joint 3 is connected to the lower end of the pressure transmitting element 2, and the 4 is connected to the universal joint 3.
The press support 1 is inserted into the through hole 6a of the pillar 6 projecting from the work supporting jig 5 fixed on the work table 1b of the press 1, and slides coaxially with the central axis A of the pressure head 1a and the universal joint 3. Press-fit head supported freely, 7 is a shaft
A turntable 8 is loosely fitted to 7a, and is a motor as a work held by the chassis 9 of the work supporting jig 5 so that its axis coincides with the central axis A, and 10 is provided in the through hole 6a of the column. A position sensor which is provided and detects the amount of displacement of the sliding press-fitting head 4 is an alarm which issues an alarm based on detection signals from lower limit and upper limit pressing force detecting means of the position sensor 10 and the pressure transmitting element 2 which will be described later. It is a device.

The alarm device 11 includes a sensor output detection unit 11a that detects an on / off detection signal output from the pressure transmission element 2,
A pressure input height detection unit 11b that detects the stroke end of the press-fitting head 4 based on a signal that represents the amount of displacement output from the position sensor 10, and a level that classifies the levels of the detection signals from the detection units 11a and 11b. A level holding section 11f having a classifying section 11c and automatic and manual resetting sections 11d and 11e for holding the level signal from the level classifying section 11c, and output from the level holding section 11f via a monitor display circuit 11g. A monitor that displays the pressure input height by indicating with a lamp or buzzer that the pressure applied by the pressure head 1a is too high (Hi), too low (Lo), or appropriate (Go), respectively, based on the signal that is generated. It consists of a display unit 11h.

FIG. 2 is a vertical cross-sectional view showing the outline of essential parts of the pressure transmission element 2 and the alarm device 11. This pressure transmitting element 2 is
A cup-shaped spring support ring 22 having a mounting screw 22a for the pressure head 1a is screwed onto the upper end of the cylindrical cylinder body 21 so as to be able to advance and retreat in the axial direction, while a lid-shaped reference is attached to the lower end of the cylinder body 21. A plate 23 is screwed into the base hole 23a of the reference plate, and a bearing cylinder 24 having an insulating sleeve 24a, a brim-shaped insulating washer 24b, and a contact ring 24c is integrally fitted and fixed in the central hole 23a. , Universal ball from below
Flange-shaped upper limit stopper 26 with 25, upper limit sleeve 2
7, an upper limit adjusting screw 28, a piston 30 formed by sequentially screwing or engaging a cup-shaped spring support sleeve 29 abutting on the inner surface of the reference plate 23 is slidably fitted in the axial direction, and further the spring A coil spring 31 is contracted between the support ring 22 and the spring support sleeve 29.

The piston 30 that abuts the work 8 through the universal ball 25 forming the universal joint and the press-fitting head 4 (see FIG. 1) is moved downward to the pressing head 1a.
A spring support ring 22 fixed to it (see FIG. 1) 22
When the pressing force is applied via the coil spring 31 and the pressing force becomes larger than the spring force of the compressed coil spring 31, that is, the lower limit pressing force, the coil spring 31 contracts in the direction of the arrow X and the spring The support sleeve 29 moves away from the inner surface of the reference plate 23. When the coil spring 31 is further contracted in the direction of the arrow X and the pressing force reaches the upper limit pressing force, the upper limit stopper 26 moves the contact ring 24c of the bearing cylinder 24 before the upper limit adjusting screw 28 contacts the spring support ring 22. The pressing force from the pressurizing head 1a is directly transmitted to the upper limit stopper 26 via the reference plate 23 of the cylinder body 21. The spring force of the coil spring 31, that is, the lower limit pressing force can be increased or decreased by advancing and retracting the spring support ring 22 in the axial direction, and the upper limit pressing force is rotated by the spring support sleeve 29 with respect to the upper limit adjustment screw that is not axially movable. By rotating the upper limit sleeve 27 which is engaged as much as possible, the upper limit sleeve 27 can be projected and retracted in the axial direction to increase or decrease. A lock screw 32 is screwed onto the tip of the upper limit adjusting screw 28 of the piston 30, and the upper limit stopper 26 is constantly pressed by the lock screw 32 via a steel ball 33, whereby the upper limit stopper 26 is axially moved. It is locked without rattling, and the pressing force received by the spring support sleeve 29 is accurately transmitted to the center in the axial direction.

On the other hand, the lower limit / upper limit pressure detection means and the main part of the alarm device 11 shown in the circuit diagram of FIG.
The (+) side of the power source 34, which is connected to the (-) side at point a of 26, is connected to the point b at the cylinder body 21 via a series resistor 35, an LED 36 and a buzzer 37 in parallel therewith, Is connected to a point c of a contact ring 24c of a bearing tube 24 insulated from the cylinder body 21 via a resistor 38, an LED 39 and a buzzer 40 arranged in parallel therewith. When the pressure applied from the pressure head 1a is less than the lower limit pressure, the cylinder body 21
When the point b of the upper limit stopper 26 and the point a of the upper limit stopper 26 are electrically connected to each other via the reference plate 23 and the spring sleeve 29 which are in contact with each other, the LED 36
Lights up and the buzzer 37 sounds to notify that the pressure is too low, and the pressure exceeds the upper limit, and the contact ring 24
When the point c of the c and the point a of the upper limit stopper 26 are brought into contact with each other for conduction, the LED 39 lights up and the buzzer 40 sounds to notify that the applied pressure is excessive. That is, the LEDs 36 and 39 are
They correspond to the Lo lamp and the Hi lamp of the monitor display section 11h in FIG. 1, respectively.

FIG. 3 is a vertical cross-sectional view of a universal joint connected to the lower end of the pressure transmission element 2. The universal joint 3 is a universal ball mounted rotatably in the center of the upper limit stopper 26 at the lower end of the pressure transmission element 2.
25 and a T-shaped protrusion 41 provided at the center of the upper end of the press-fitting head 4.
Has a notch 42a that engages with, and has a U-shaped cross section and is fixed to the lower surface of the upper limit stopper 26 with screws 43, 43.
Consists of. And the pressure transmission element 2 and the press-fitting head 4 are
The center axes of the press-fitting heads 4 are arranged so as to form a straight line A, and when the pressurizing head (see 1a in FIG. 1) is raised, the press-fitting head 4 is pulled up through the connecting fitting 42 as shown in FIG. 3 (a). When the pressurizing head is lowered, the press-fitting head 4 is vertically pushed down via the universal ball 25 and the projection 41 without any axial deviation, as shown in FIG. 3 (b).

The operation of the press-fitting device having the above structure will be described below with reference to FIG. 1 including an embodiment of the press-fitting method of the present invention.

The lower end of the pressurizing head 1a of the press 1 is a pressure transmission element 2, a universal joint 3, and a press-fitting head 4 which are sequentially connected to each other. A support 6 of a work supporting jig 5 fixed on the work table 1b.
The axis is aligned with the vertical line A so that it can be lifted and lowered. Further, the spring force of the coil spring 31 of the pressure transmission element 2 is exerted between the cylinder body 21 and the piston 30 by moving the spring support ring 22 (see FIG. 2) in the axial direction, so that a lower limit of 8 kg is applied. Under pressure, the coil spring 31 will move to the arrow X
The spring support sleeve 29 is adjusted so as to be retracted from the reference plate 23 by contracting in the direction, while the protrusion amount S of the upper limit sleeve 27 is
By turning the upper limit sleeve 27, the coil body 31 is contracted most under the upper limit pressure of 15 kg working between the cylinder body 21 and the piston 30, so that the upper limit stopper 26 abuts the contact ring 24c of the bearing cylinder 24. Has been adjusted.

Now, on the work supporting jig 5 fixed to the press 1, the work in which the press-fitting hole of the turntable 8 is loosely fitted to the motor shaft 7a of the motor 7 is arranged so that their central axes coincide with the vertical line A. And is held and fixed by the chassis 9. Next, the press 1 is driven to lower the pressure head 1a, and the work is pressed toward the work table 1b via the pressure transmission element 2, the universal joint 3, and the press-fitting head 4.

At this time, the pressure of the pressure head 1a is 8 kg (lower limit pressure)
If it is less than this, as shown in FIG. 2, the point b of the cylinder body 21 and the point a of the upper limit stopper 26 are conducted through the reference plate 23 and the spring support sleeve 29 that are in contact with each other, and the LED 36 lights up.
Since the buzzer 37 sounds, when the works 8 and 7a are press-fitted in such a state, it can be determined that the press-fitting is too small and the work is loosely fitted to cause the turntable 8 to idle when used. If the pressing force of the pressure head 1a exceeds 15 kg (upper limit pressing force), the point c of the contact ring 24c of the bearing tube 24 and the point a of the upper limit stopper 26 are brought into contact with each other to conduct electricity, and the LED 39 lights up and the buzzer sounds. 40 sounds, so work 8
When 7a is press-fitted, it can be determined that the press-fitting is excessive, the work is tightly fitted, and the motor shaft 7a is bent or the like, causing surface wobbling or the like of the disk during use. Needless to say, the above lower and upper limits can be adjusted freely.
Further, the pressure force from the pressure head 1a is accurately transmitted to the axial center of the upper limit stopper 26 via the lock screw 32 and the steel ball 33 in the pressure transmission element 2 and further via the universal ball 25. And press-fit head 4
Is transmitted to the axial center of. That is, conventionally, as shown in FIG. 4 (a), no matter how the axes of the press-fitting head 4 and the works 8 and 7a are held on the vertical line A, the pressing direction of the pressing head 61a is inclined. The force point P is eccentric from the central axis by e, which causes the operation of the press-fitting head 4 to be distorted, and the increase in the frictional resistance of the sliding contact surface makes it impossible to properly manage and control the pressing force. In this embodiment, as shown in FIG. 4 (b), the universal ball 25 at the lower end of the upper limit pulse 26 always transmits the pressing force straightly on the vertical line A to the works 8 and 7a, and the force input in the oblique direction is It does not occur at all. Therefore, the lower limit of the pressure transmission element 2 described above,
The upper limit pressure can be managed and controlled accurately.

In the above-mentioned embodiment, the work 8, 7a is mechanically separated from the pressure head 1a of the press 1 which has rattling associated with lifting and lowering mechanical precision and is mechanically separated from the pressure head 1a which is vertically held by the column 6. Since the press-fitting head 4 operates smoothly, there is an advantage that the pressure-transmitting element 2 can accurately manage and control the lower and upper limits of the pressurizing force, and can eliminate defective press-fitting. In addition, the pressure transmission element 2
Of the coil spring 31 by moving the spring support ring 22 of the
Of the cylinder body 21 and the spring support sleeve 29 of the piston 30 constitute the lower limit pressure detection means, while the upper limit sleeve 27 is rotated. The upper limit sleeve 27 is axially retracted so that the upper limit pressure can be adjusted, and the contact between the contact ring 24c of the bearing tube 24 of the cylinder body 21 and the upper limit stopper 26 of the piston 30 constitutes the upper limit pressure detection means. Therefore, it is possible to manage the pressure input within the range of the lower limit and the upper limit pressure that are set arbitrarily, and it is possible to immediately know whether the pressure input is too small or too large during the press-fitting work by the alarm means, and it is possible to eliminate the press-fitting failure. There are advantages. Further, the pressure transmission element 2 of the present embodiment has an advantage that the press-fitting load can be known at the same time as the press-fitting, as compared with the conventional load cell, and the structure is simple and the manufacturing cost is 1/10 or less.

FIG. 5 is a bearing showing another embodiment of the press-fitting method of the present invention. The press-fitting device used in this press-fitting method has the same structure as that of FIG. 1 except that a guide pin 45 which is a direct work is used instead of the press-fitting head 4 of the press-fitting device described in FIG. The same numbers are given to the members, and the description will be omitted. In this embodiment, the guide pins 45 are press-fitted into the press-fitting holes 46a at the four corners of the precision mold plate 46,
The guide pin 45 is coaxially connected to the press head 1a of the press via the universal joint 3 and the pressure transmission element 2, and is a support column projecting from the work supporting jig 5 fixed to the work table 1b of the press. 6 and a holding plate 48 fixed to the support column 6 with bolts 47, 47 to hold the V groove 6a.
It is slidably supported in the vertical direction. Further, the mold plate 46 is fixed on the work supporting jig 5 with the center of the press-fitting hole 46a positioned directly below the guide pin 45. Therefore, since the universal joint 3 pushes the center of the guide pin 45 vertically toward the press-fitting hole 46a, the operation of the pressure transmitting element 2 and the like and the press-fitting process are not different from those of the above-described embodiment and are the same as those described above. Produces the action and effect of.

In the embodiment shown in FIG. 1, the shaft 7a side is supported by the work supporting jig 5. However, when a large number of bearings are fitted to the shaft, the press-fitting hole side bearing is used as the work supporting jig 5. It is also possible to support and press the shaft side with the press-fitting head 4. Further, it goes without saying that the press-fitting method and device of the present invention can be widely applied to press-fitting and fitting of precision parts to each other as well as press-fitting of a turntable and a motor shaft of a compact disc player.

<Effects of the Invention> As is apparent from the above description, in the press-fitting device of the present invention, the piston is movably arranged in the cylinder, and the spring is compressed so that the spring force can be adjusted between the piston and the cylinder. ,
A pressure transmitting element for transmitting a pressing force from the cylinder to the piston via the spring is connected to the tip of the press head of the press via the cylinder, and the universal joint is connected to the piston, while the press-fitting method of the present invention. Is pressurizing the work placed on the work table of the press by using the press-fitting device with the pressurizing head through the universal joint and the pressure transmitting element and pressurizing, for example, the spring force as desired. Adjust so that the piston starts to move relative to the cylinder under the lower limit pressure, and detect the separation of the spring from the cylinder by the lower limit pressure detection means, while the amount of protrusion of the piston is adjusted under the desired upper limit pressure. Make the piston contact the cylinder against the spring,
The contact of the piston with the cylinder is detected by the upper limit pressure detection means, and the alarm means issues an alarm based on the detection signals from both detection means. Properly manage the pressure applied to the workpiece,
It is possible to control, and it is possible to always apply a straight pressure force to the work in a vertical direction by the universal joint, and the verticality is maintained within a proper range of pressure force with an inexpensive device with a simple structure. Press-fitting can be realized, and the reliability of precision parts and the efficiency of press-fitting work can be significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a press-fitting device used for carrying out the press-fitting method of the present invention, FIG. 2 is a longitudinal sectional view of the pressure transmission element of FIG. 1, and FIG. 3 is a universal joint of FIG. FIG. 4 is a detailed longitudinal sectional view of FIG. 4, FIG. 4 is a view showing a press-fitting state according to the above-described embodiment and a conventional example, FIG. 5 is a perspective view showing another embodiment of the present invention, and FIG. 6 is a side view showing a conventional press-fitting device. FIG. 7 and FIG. 7 are views showing a press-fitted state according to the conventional example. 1 ... Press, 1a ... Pressure head, 1b ... Work table, 2 ... Pressure transmitting element, 3 ... Universal joint, 4 ... Press-fit head, 5 ... Work support jig, 6 ...
Support, 7 ... motor, 7a ... motor shaft, 8 ... turntable, 10 ... position sensor, 11 ... alarm device, 21 ...
Cylinder body, 30 …… Piston, 31 …… Coil spring.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Haruyama 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (56) References: 63-35531 (JP, U) Actual: 57 −100433 (JP, U) Actually open 52-101083 (JP, U) Actually open 1-128997 (JP, U)

Claims (2)

[Claims] 1. A pressure for transmitting a pressing force from a cylinder to a piston via a spring, in which a piston is movably arranged in a cylinder, a spring is contracted between the piston and the cylinder so that a spring force can be adjusted. The transmission element is connected to the tip of the press head of the press, the universal joint is connected to the pressure transmission element, and the pressure transmission element is
With a lower limit pressure detection means for detecting the time when the piston starts relative movement to the cylinder against the spring, and an upper limit pressure detection means for detecting the time when the piston contacts the cylinder against the spring, The work placed on the work table of the press is press-fitted by the pressurizing head through the universal joint and the pressure transmission element, and press-fitted to issue an alarm based on the detection signals from the both detecting means. Method. 2. A pressurizing head of a press, a piston is movably arranged in a cylinder, and a spring is compressed between the piston and the cylinder so that a spring force can be adjusted.
Pressurizing force is transmitted from the cylinder to the piston through this spring, and the lower limit pressing force detecting means for detecting the time when the piston starts to move relative to the cylinder against the spring, and the piston against the spring and the cylinder Pressure transmitting element having an upper limit pressure detecting means for detecting a time point of contact with the pressure transmitting element, a universal joint connected to the pressure transmitting element, and a work table of the press slidable coaxially with the center axis of the work. A press-fitting device including a press-fitting head supported by the above-mentioned universal joint and alarming means for issuing an alarm based on detection signals from both the detecting means.