JPH0616972B2 - Shrink-fitting method and device for member - Google Patents

Description

The present invention relates to a method for shrink-fitting a member and an apparatus therefor.

[Conventional technology]

In the case where the heavy-weight crankshaft side assembly member of a hermetic compressor as described in Japanese Utility Model Laid-Open No. 47-212203 and the rotor of a relatively light electric motor are shrink-fitted and fixed, heating is required. The rotor had been shrunk and fixed so as to fall from above the crankshaft. When this method is incorporated in the automatic assembling process of the fully hermetic compressor, when assembling the compressor part with the crankshaft, the method of assembling with the tip of the crankshaft facing downward is easy to assemble. Assembly is completed in the downward position. During the next shrink-fitting process of the crankshaft and rotor, it is easy to shrink-fit the crankshaft side with the compressor part at the bottom, so turn the crankshaft tip upside down. I've been there since.

[Problems to be solved by the invention]

The above-mentioned prior art does not give sufficient consideration to the point that the assembly work control becomes complicated when it is incorporated into the automatic assembly process of the hermetic compressor, because the inversion process of the crankshaft side member is involved. However, there were problems such as upsizing of automatic assembly equipment and increase of equipment cost.

An object of the present invention is to provide a method and apparatus for shrink-fitting a member suitable for automatic assembly of a hermetic compressor.

[Means for solving problems]

A feature of the present invention is that one of the two members is heat-fitted and fixed by shrink fitting, and air pressure is applied to the lower surface of the one heating member that is shrink-fitted and fixed so as to levitate, and while this air pressure is applied to slightly vibrate. Using a method of pressing a heating member from below and fitting and shrink-fitting it, a heating device for heating one member that is shrink-fitted, a transfer device for transferring the heating member to a predetermined position, and the predetermined position. A fixing device for fixing and positioning the other shrink-fitting fitting member above the heating member transferred to the heating member, and guiding the heating member to the fitting portion of the mating member below the heating member to perform shrink-fitting fitting. After the heating member is guided to the mating position of the mating member by the shrink fit fitting force applying means for applying the resultant force and the guide, the air pressure is intermittently supplied to the lower surface of the heating member to show the heating member. To provide an air pressure supply device that gives vibration That.

[Action]

When fitting the two members by shrink fit, the member arranged at the bottom of the upper and lower members is heated by the heating device, and the fitting force is given by the shrink fit fitting force imparting means toward the upper member. Is given to move the lower member. At this time, air pressure is continuously supplied to the lower surface of the member to be moved by the air pressure supply device to levitate the heating member, and the vibration is applied by this air pressure to facilitate the insertion operation. Also,
By supplying the air pressure, the members are brought into a floating state, and the shaft centers of both the members that are shrink-fitted can be accurately matched.

As a result, it is possible to obtain a shrink fitting method and apparatus for members suitable for automatic assembly of a hermetic compressor.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

Reference numeral 1 denotes a compressor section, in which spiral wraps of a fixed scroll and an orbiting scroll are engaged with each other, and a crankshaft 2 inserted into an orbiting bearing of the orbiting scroll is supported by a bearing provided on a frame, and a rear surface of the orbiting scroll is provided. Is provided with a rotation prevention mechanism.

3 is a rotor of the electric motor, which is in a heated state. 4 is a stator. Reference numeral 6 indicates a closed container in which the compressor unit 1 and the stator 4 are fixed. The closed container 6 is positioned by the positioning member 5 and set at a predetermined position.
A pallet 21 is formed integrally with the positioning member 5 and has a hole 21 sufficient to allow the rotor 3 to pass therethrough at the center thereof.
Have one.

22 is a chain conveyor provided in two rows,
It is connected to a drive device (not shown) and is mounted so that the pallet 21 can be placed and moved. Two
Reference numerals 9 and 30 are positioning holes for the pallet 21. 23,
A positioning cylinder 24 is provided with pins 25 and 26 that can move in the vertical direction, and is hydraulically driven, for example.

27 and 28 are the ends of the pins 25 and 26, and are the holes 29 and 30.
The pallet 21 is positioned when it is inserted into. 31
Is connected to a hydraulic device or the like by a holding cylinder and has a function of moving the rod 311 in the vertical direction. Three
A pressing member 2 is provided at the tip of the rod 311 and has a function of pressing when the closed container 6 is positioned on the pallet 21. The holding cylinder 31 is attached to the stay 312, and the stay 312 is mounted on the column 3
It is fixed at 13.

This support column 313 is attached via a base plate 314 to a mounting base plate 315.
It is fixed to. 33 is a turntable 38
It is rotatably provided around a main column 332 on a roller 331 provided at the upper end of the. 333 is a roller receiver.
Denoted at 34 are pedestals, which are provided on the outer circumference of the turntable 33 at three positions at 120 ° intervals. Reference numeral 3'denotes a state in which the rotor is heated and then rotated by 120 ° and positioned at a predetermined position. Reference numeral 341 is a hole penetrating the pedestal 34. A heating coil 35 is wound around the cylinder 351 and both ends thereof are connected to an oscillator 37 installed in a heating device 371 through a terminal block 352.

A push-up cylinder 36 is configured to be hydraulically driven, and is attached to the indexing base 38 via a bracket 361.

A rod 362 is attached by a rod so as to be movable in the vertical direction in the cylinder 36, and a wapper 363 and a pin portion 364 are formed at the tip, and the pin portion 364 is guided on the wapper 363 and inserted into the hole 50. The rotor 3 is mounted. Then, the rotor 3 is pushed up by the operation of the piston 36 to a position where it is easily heated by the coil 35. A guide bar 39 is connected to the cylinder 40. A push-up rod 42 is formed in a tubular shape and accommodates the guide bar 39 therein. Reference numeral 45 is an air passage formed between the guide bar 39 and the inner wall of the cylindrical push-up rod 42. The guide bar 39 and the push-up rod 42 are provided at positions coaxial with the hole 50 of the rotor 3'and the crankshaft 4.

Reference numeral 41 is a cylinder that slidably accommodates a rod 43 and is connected to a hydraulic drive source. Reference numeral 47 is a fixed base, which is connected to the tip of the rod 43. The slide body 62 is attached to the fixed base 47 along the slide base 61 attached to the pillar 60 so as to be slidable in the vertical direction. The shrink fitting force supplying means is composed of the cylinder 41, rod 43, fixing base 47, slide base 61, guide bar 39, push-up rod 42, and the like.

Reference numeral 46 denotes an air passage, one end of which communicates with the air passage 45, and the other end of which is connected to a high pressure air generator (not shown) via a hose 48.

In FIG. 2, 63 is a bearing, and 451 is a plurality of air passages provided on the outer periphery of the bearing 63, which communicate with the air passage 45.

Next, the operation will be described.

The rotor 3 of the electric motor is placed on the receiving table 34 of the turntable 33 by another means, and is transferred to the position just below the heating coil 35 by controlling the operation of the indexing table 38. The heating coil 35
When the rotor 3 is transferred to the position immediately below the rod 3, the push-up cylinder 36 is actuated and the pin 364 at the tip of the rod 362 is operated.
Is placed in the hole 50 of the rotor 3, placed on the wapper 363, and further pushed up and inserted into the cylinder of the heating coil 35.
At this position, the push-up cylinder 36 maintains the stopped state. Next, the oscillator 37 is operated to supply a high frequency current of about 25 KHz to the heating coil 35. As a result, an induced current flows on the surface of the rotor 3 in the heating coil 35, Joule heat is generated, and the rotor 3 generates heat. Rotor 3
Is detected by a detection means (not shown) that it has been heated to a predetermined temperature, or when a predetermined time elapses, the push-up cylinder 36 starts to operate again, lowers the rod 362, and heats the rotor 3 again onto the wapper 363. Return, rod 362
Is further lowered and controlled to stop at a position lower than the turntable 33. Next, the turntable 33 on which the heated rotor 3 is mounted is rotated by 120 ° by the operation control of the indexing table 38, and the rotor 3 heated by this rotation is rotated.
Is positioned at a position where the axis of the guide bar 39 and the axis of the hole 50 of the rotor 3 are aligned. At the same time, the pallet 21 is positioned so as to coincide with the axis of the crankshaft 2'of the compressor unit 1 fixed in the closed container 6 on the pallet 21. Next, the cylinder 4 is driven by a driving means (not shown).
The pressure oil is sent to 1, the rod 43 is moved, and the fixed base 47 connected to the rod 43 is slid along the base 61. As a result, the upper end surface of the push-up rod 42 eventually contacts the lower surface of the heated rotor 3 '. At the same time, the cylinder 40 is actuated by a driving means (not shown) to insert the guide bar 39 into the hole 50 of the rotor 3'and approximately the height of the rotor 3 '.

This completes the preparation for separating the rotor 3'from the pedestal 34.

Next, the cylinder 41 is operated to further raise the fixed base 47, and the rotor 3'is separated from the receiving base 34 and pushed up until the state of FIG. 2, that is, the tip of the guide bar 39 comes into contact with the end surface of the crankshaft 2.

From the state shown in FIG. 2, the guide bar 39 is then pulled down, and high pressure air is guided from the air passages 46 and 45 to the space 452 through the air passage 451 through the hose 48 connected to the high pressure air generator, and then to the space 452. The blown high-pressure air serves as a force for pressing the lower surface of the rotor 3'and the lower surface of the crankshaft 2. In this way, the hole 50 and the crankshaft 2 are centered while applying a force to levitate the rotor 3 ', the cylinder 41 is operated, and the rotor 3'is pushed up by the tip of the push-up rod 42 and fitted to the crankshaft 2. Shrink fit and stick. FIG. 3 shows a state where the fitting shrink fit has been completed.
The time required for this fitting shrink fit is several seconds. High pressure air is several kg / cm ² and does not require a particularly high pressure. Since the heated rotor 3'is given a vibration of vibration when pushed up, it tries to rotate to some extent. In order to prevent this, a stopper 421 is provided at the tip of the push-up rod 42, and is brought into contact with the side surface of the balance weight 300 attached to the end of the rotor 3'to prevent rotation. High-pressure air is supplied while the shrink fit is in progress. The rotor 3'is levitated by the high-pressure air. When levitated, the tip end surface 422 of the push-up rod 42 and the contact surface 301 of the rotor 3'are separated from each other to form a gap. When the high-pressure air escapes from the gap, the high-pressure air temporarily loses the force of floating.
Therefore, the rotor 3'falls down. Since the gap is closed again by the drop, a force for floating by the high pressure air is generated.

In this way, the rotor 3'is repeatedly vibrated and dropped, and is vibrating. While maintaining such a slight vibration state, the rotor 3 ′ heated by the push-up rod 42 is pushed up to a predetermined position for a certain period of time, and the shrink fit is completed by natural cooling. When the shrink fit is completed, the push-up rod 42 is lowered. In this way, the closed container 6 in which the rotor is shrink-fitted and fixed is moved to the next assembling step by the chain conveyor 22 together with the pallet 21.

Next, an automatic assembling process of the hermetic compressor including the shrink fitting process of the rotor 3 and the crankshaft 2 will be described.

FIG. 6 shows the outline of the automatic assembling process of the hermetic compressor. FIG. 6A shows a step of preparing a compressor assembly in which the compressor section 1 and the crankshaft 2 are assembled.

FIG. 6 (b) shows a centering process between the compressor assembly prepared in the previous process and the stator 4 of the motor, and a fixing process by welding with the closed container 6. For centering, the crankshaft 2 is first centered by the jig 10, and then another jig 11 is fitted on the outside of the jig 10 to center the stator 4. When the centering of the both is completed, the compressor assembly and the stator 4 are housed in the inside by covering the hermetically sealed container 6 from the upper side, and fixed by shrinkage fitting.

Then, from the outside of the closed container 6, the outer peripheral portion of the compressor unit 1 and the closed container 6 are fixed by welding at a point 7 point. When the welding and fixing are completed, the jigs 10 and 11 are taken out and moved to the next step.

FIG. 6 (c) shows a state in which the rotor 3 is shrink-fitted and fixed to the crankshaft 2. The shrink fitting method and apparatus are as described above. That is, the characteristic of this step is that the method of shrink-fitting the rotor 3 and the crankshaft 2 is fixed, but conventionally, the closed container 6 is inverted and the tip of the crankshaft 2 is set upward, and the rotor 3 is dropped from above. The present invention does not change the downward state of the crankshaft 2 from beginning to end, and the rotor 3 is pushed up while applying the vibration to the heated rotor 3 from below without constantly changing the downward state of the crankshaft 2. The point is that they are fixed by shrink fitting. This is useful for reducing the number of assembling steps and reducing the size of the assembling apparatus by reducing the number of assembling steps in the automatic assembling of the hermetic compressor. FIG. 6 (d) shows a process in which the cap 8 and the closed container 6 are welded all around at the point 9 and closed.

According to the present embodiment, since the shrink fit of the rotor can be pushed up from below, it is possible to eliminate the reversal work having no added value. Further, since there is no reversing work, the automatic assembling apparatus becomes simple.

Moreover, the assembly time can be shortened due to the reduction in the number of steps, and the assembly can be performed in a short time.

〔The invention's effect〕

According to the present invention, it is possible to obtain a method and an apparatus for shrink-fitting a member suitable for automatic assembly of a hermetic compressor.

[Brief description of drawings]

FIG. 1 is a schematic overall view of a rotor shrink-fitting apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of an essential part showing an initial state diagram during shrink-fitting processing, and FIG. FIG. 4 is an enlarged sectional view of an essential part showing a state diagram at the end of processing, FIG. 4 is a sectional view taken along line AA of FIG.
FIG. 5 is a view on arrow B of FIG. 2, and FIG. 6 is a conceptual diagram of the automatic assembly process. 1 ... Compressor section, 2 ... Crank shaft, 3 ... Rotor, 4
... stator, 5 ... positioning member, 6 ... closed container,
8 ... Cap, 21 ... Pallet, 22 ... Chain conveyor, 23, 24 ... Positioning cylinder, 31 ...
… Presser cylinder, 34 …… Base plate, 35 …… Heating coil,
36 ... push-up cylinder, 37 ... oscillator, 38 ... indexing table, 39 ... guide bar, 40, 41 ... cylinder,
42 ... Pushup rod.

Claims (2)

[Claims] 1. In one in which one of two members is heated and shrink-fitted and fixed, air pressure is applied to the lower surface of one heating member that is shrink-fitted and fixed to make it float, and this air pressure causes a downward vibration while applying a characteristic vibration. A method for shrink-fitting a member, which comprises press-fitting a heating member to fit and shrink-fit it. 2. A heating device for heating one of two members and shrink-fitting the same, and a heating device for heating the one member fitted by shrink-fitting, and a transfer device for transferring the heating member to a predetermined position. A fixing device for fixing and positioning the other shrink-fitting fitting member above the heating member transferred to the predetermined position, and guiding the heating member to the fitting portion of the mating member below the heating member. After shrink-fitting force applying means for applying a shrink-fitting force and the guide to guide the heating member to the mating position of the mating member, air pressure is intermittently supplied to the lower surface of the reheat member. A shrink fitting device for a member, which comprises an air pressure supply device for applying a vibration to the heating member.