JP2003034168A - Gear box device and fixing method for cap member thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear box device with excellent workability of fixing capable of fixing a cap member to a housing without depending on screwing in a gear box device comprising a casing for rotatably supporting a gear shaft and a cap member fixed to the casing to regulate the axial movement of the gear shaft, and a fixing method for the cap member. SOLUTION: The cap member 27 is ultrasonically welded to the casing 21 of the gear shaft.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gear box device having a gear shaft and a method for fixing a cap member thereof.

[0002]

2. Description of the Related Art For example, in a power seat device of a vehicle, the rotational driving force of a motor is transmitted to a gear shaft in a gear box device, and the rotation of the gear shaft is converted into the rotational movement of a feed screw shaft. By rotating the feed screw shaft, the front-back position and the vertical position of the seat are adjusted.

The gear box device has, for example, a gear shaft made of a worm and a worm wheel which rotates in response to the rotation of the gear shaft, and a feed screw shaft is integrally connected to a shaft portion of the worm wheel. . When assembling this gear box device, in order to regulate the axial movement of the gear shaft rotatably supported in the housing,
The cap member is fixed to the housing. Conventionally, this cap member has been screwed to the housing,
Screw connection is often caused by looseness of the gear shaft, variations in screw tightening force, deformation due to excessive tightening force, housing cracking, uneven contact due to inaccuracy of the cap member, and screw accuracy when the cap member is injection molded. There was a problem.

[0004]

SUMMARY OF THE INVENTION The present invention is based on the above-mentioned awareness of the problems of the conventional gear box device having a cap member.
An object of the present invention is to provide a gear box device which is capable of fixing a cap member to a housing without screwing and which has excellent fixing workability, and a method of fixing the cap member.

[0005]

SUMMARY OF THE INVENTION According to the present invention, when the casing and the cap member are both made of a material suitable for ultrasonic welding such as a synthetic resin material, and both are welded by an ultrasonic welding technique, the fixing workability is excellent, This is done based on the idea that various conventional problems can be solved at once. That is, according to the present invention, in a gear box device having a casing that rotatably supports a gear shaft and a cap member that is fixed to the casing and restricts axial movement of the gear shaft, the cap member is ultrasonically welded to the casing. It is characterized by having done.

There are various concrete structures for restricting the axial position of the gear shaft with the cap member. For example, the gear shaft is fixed to the inner ring of the ball bearing, and the outer ring of the ball bearing is used as the bearing support surface of the casing. It is possible to employ a structure in which the cap member is sandwiched and held. In this aspect, for example, the cap member is provided with an insertion cylindrical portion whose one end abuts the outer ring and a top plate flange portion located at the other end of the insertion cylindrical portion, and the cap member is inserted into the casing. The tubular portion is inserted, and a receiving tubular portion with which the top plate flange portion abuts is formed on the end surface thereof.
Then, the inner peripheral edge portion of the receiving tubular portion of the casing and the boundary portion between the top plate flange portion of the cap member and the insertion tubular portion are ultrasonically welded. In order to effectively ultrasonically weld the boundary portion, it is desirable that the boundary portion be composed of an axis of the insertion cylindrical portion and a tapered surface inclined with respect to a surface orthogonal to the axis.

In another mode, the cap member has an insertion cylindrical portion whose one end abuts on the outer ring of the ball bearing, a top plate flange portion located at the other end of the insertion cylindrical portion, and this top plate flange. The casing has a plurality of caulking holes, and the casing has a receiving tubular portion into which the insertion tubular portion of the cap member is inserted and the top plate flange portion abuts on the end surface, and an end surface of the receiving tubular portion. And a plurality of caulking projections that are inserted into the respective caulking holes. Then, the caulking projection and the caulking hole are ultrasonically welded.

In the aspect of the cap member fixing method according to the present invention, there is provided a gear box device having a casing for rotatably supporting the gear shaft and a cap member fixed to the casing for restricting axial movement of the gear shaft. In the step of applying the cap member to a position that restricts the axial movement of the gear shaft of the casing; and applying ultrasonic vibration to the cap member while maintaining the positional relationship between the cap member and the casing. And a step of welding the cap member and the casing by frictional heat generated by vibration.

[0009]

FIG. 8 and FIG. 9 show a vehicle power seat device to which the gear box device of the present invention is applied. The seat track device 10 is located between the left and right lower surfaces of the seat S and the vehicle floor surface F, respectively. The seat track device 10 includes a lower rail 11 fixed to a vehicle floor surface F and an upper rail 12 fixed to a lower surface of the seat S. The upper rail 12 includes a gear box device 20 which is a target of the present invention, and the gear box device 20. A feed screw shaft 13 that is rotationally driven by the box device 20 and a motor unit 14 that is a drive source of the gear box device 20 are supported. The feed screw shaft 13 is oriented in the front-rear direction of the vehicle and is supported so as to be freely rotatable with respect to the upper rail 12 so as not to move relative to the axial direction. Lower rail 11
A nut body 15 screwed onto the feed screw shaft 13 is fixed to the. Therefore, when the feed screw shaft 13 is rotationally driven in the forward and reverse directions via the gear box device 20, the feed screw shaft 1
The upper rail 12 (seat S) itself having 3 moves in the front-rear direction of the vehicle, and the front-rear position of the seat S is adjusted.

1 to 3 show a first embodiment of a gear box device 20 according to the present invention. The gear box device 20 includes a pair of split casings 2 made of synthetic resin.
Have one. The pair of divided casings 21 are joined together by a fixing bolt nut 21X to be integrated,
Each has a split storage recess 23 that stores the worm shaft (gear shaft) 22, and a split storage recess 25 that stores the worm wheel 24 that meshes with the worm shaft 22. The axis of the worm split storage recess 23 (worm shaft 22) and the axis of the worm wheel split storage recess 25 (worm wheel 24) are orthogonal to each other.
In the worm split storage recess 23, the motor unit attachment / detachment holes 23 of the motor unit 14 are sequentially provided from the left side of FIG.
a, a bearing hole 23b, a worm bore 23c, and a seat 2 for a ball bearing 26 having a diameter larger than that of the worm bore 23c.
Receiving cylindrical portion 23 for inserting and fixing 3d and cap body 27
e is formed. The inner diameter of the receiving cylindrical portion 23e is larger than the inner diameter of the ball bearing storage seat 23d, and the axial length of the ball bearing storage seat 23d is shorter than the axial length of the ball bearing 26.

The worm wheel divided storage recess 25 has a circular recess 25a communicating with the worm bore 23c, and a shaft hole 25b formed in the shaft of the circular recess 25a. The worm wheel 24 inserted into the circular recess 25a of the divided storage recess 25 has a feed screw shaft 13 serration-coupled to its shaft portion, and the feed screw shaft 13 projects outward from the shaft hole 25b. Both ends of the worm wheel 24 have a pair of worm wheel divided storage recesses 25.
It is sandwiched by the walls of the (circular recess 25a), and its axial movement is restricted.

The worm shaft 22 has a sliding shaft portion 22a that is rotatably supported in a bearing hole 23b of a worm split storage recess 23, a worm portion 22b located in a worm bore 23c, and a small diameter portion for mounting a ball bearing 26. 22c and the male threaded portion 2 located in the receiving tubular portion 23e
2d, and a non-circular cross-section hole 22a 'is opened at the end surface of the sliding shaft portion 22a.

The cap member 27 made of synthetic resin has an insertion tubular portion 27a inserted into the receiving tubular portion 23e and a top plate flange portion 27b provided at one end of the insertion tubular portion 27a.
And the top plate flange portion 27b abuts on the end surface of the receiving cylindrical portion 23e of the split casing 21. Also,
At the boundary between the outer periphery of the insertion tubular portion 27a and the top plate flange portion 27b, as shown in FIG.
A tapered surface 27c that is inclined (about 45 ° in the illustrated example) with respect to the axis of a and the plane orthogonal to the axis is formed. The tapered surface 27c is ultrasonically welded to the inner peripheral edge 23e 'of the receiving tubular portion 23e of the split casing 21,
The cap member 27 is fixed to the worm split storage recess 23 (split casing 21).

That is, in the gearbox device 20 having the above-mentioned structure, the worm shaft 22 is fitted in the worm split housing recess 23 of the split casing 21, and the feed screw shaft 13 is out of the shaft hole 25b. The worm wheel 24 is fitted to the pair and the pair of divided casings 21 are connected by the fixing bolts and nuts 21X. At this time, the sliding shaft portion 22a of the worm shaft 22 is positioned in the bearing hole 23b of the worm split storage recess 23, the worm portion 22b is positioned in the worm bore 23c, and the washer 28 and the ball bearing 26 are fitted to the small diameter portion 22c. , Male thread 22
The fixing nut 29 is screwed onto d. Then, the inner ring 26 a of the ball bearing 26 is sandwiched between the washer 28 and the fixing nut 29 and fixed to the worm shaft 22. On the other hand, the outer ring 26b of the ball bearing 26 has the ball bearing storage seat 2 of the worm split storage recess 23.
By being sandwiched between the stepped portion (edge portion) 23d ′ of 3d and the tip of the insertion tubular portion 27a of the cap member 27, the cap member 27 is ultrasonically welded to the end surface of the receiving tubular portion 23e. The axial position of the outer ring 26b is fixed.

FIG. 4 shows the cap member 27 and the receiving tubular portion 2.
3 shows an example of an apparatus for ultrasonically welding 3e.
The base 30 is provided with an ultrasonic vibration horn 32 that moves up and down by an air cylinder device 31. The air cylinder device 31 is controlled via a compressed air source 33, an air filter 34, an air circuit 35, and a controller 36. The ultrasonic vibrating horn 32 includes an ultrasonic oscillator 37 and an ultrasonic oscillator 38.
And controller 36 provides the required ultrasonic vibrations. In ultrasonic welding, the gear box device 20 is set on the receiving table 39 with the receiving tubular portion 23e facing upward, and the receiving cylinder portion 23e is covered with the cap member 27 from the air cylinder device 31. The ultrasonic vibration horn 32 is lowered and brought into contact with the top plate flange portion 27b of the cap member 27. In this set state, the ball bearing 26 is provided between the tip end portion of the insertion tubular portion 27a of the cap member 27 and the step portion 23d 'of the ball bearing storage seat 23d.
The outer ring 26b of the inner ring 26a is clamped without play.
Is fixed to the worm shaft 22 by the step portion between the worm portion 22b and the small diameter portion 22c and the fixing nut 29, so that the axial position of the worm shaft 22 is regulated.

In this set state, the ultrasonic vibration horn 32
When ultrasonic vibration is applied to the cap member 27, the tapered surface 27c of the cap member 27 vibrates ultrasonically while contacting the inner peripheral edge 23e 'of the receiving cylindrical portion 23e of the split casing 21, and frictional heat is generated on the contact surface. This frictional heat is instantaneously generated to melt the contact part and weld the melted part. At this time, if there is an imbalance between the tip end portion of the insertion tubular portion 27a of the cap member 27 and the outer ring 26b of the ball bearing 26, friction heat is generated only at the improper portion and the cap member 27 melts. Therefore, the ball bearing 26 does not play more reliably, and the insertion cylindrical portion 27a of the cap member 27 is prevented.
Will be supported between the front end surface of the step and the step portion 23d '.

5 to 7 show a second embodiment of the present invention. In this embodiment, the split casing 2
A plurality of (90 in the illustrated example) the end surface of the receiving cylindrical portion 23e.
While four caulking protrusions 23f are formed at intervals of 4 °, caulking holes 27d corresponding to the caulking protrusions 23f are formed in the top plate flange portion 27b of the cap member 27. The caulking hole 27d may be a straight hole as shown in FIG. 7A or a tapered hole as shown in FIG.

In this embodiment, as shown in FIGS. 7A and 7B, ultrasonic vibration is applied to the caulking protrusion 23f by the ultrasonic vibrating horn 32, and the caulking protrusion 23f protrudes from the cap member 27. Is melted and its head is enlarged to prevent it from coming off.

The gear box device 20 described above is combined with the motor unit 14 in the use examples shown in FIGS.
The drive shaft 14a having a non-circular cross section of the motor unit 14 is inserted into the non-circular cross section hole 22a 'of the sliding shaft portion 22a of the worm shaft 22. When the drive shaft 14a is driven to rotate in the forward and reverse directions, the worm shaft 22 rotates integrally with the drive shaft 14a in the forward and reverse directions. As a result, the worm wheel 24 and the worm wheel 24 engaging with the worm portion 22b of the worm shaft 22 are serrated. The feed screw shaft 13 that is rotating rotates in the reverse direction. The feed screw shaft 13 has an upper rail 12
The axial movement of the lower rail 11 is restricted.
Since it engages with the nut body 15 fixed to the side, the forward movement of the feed screw shaft 13 causes the upper rail 12 (seat S) to move back and forth. The screw shaft 13 may be screwed to the shaft portion of the worm wheel 24, and the rotation of the worm wheel 24 may be regulated and held so that the screw shaft 13 is moved in the axial direction by the rotation of the worm wheel 24.

Of course, the use example of FIGS. 8 and 9 is an example of the gear box device 20, and the gear box device 2 of the present invention is used.
The application device of 0 is not limited to the power seat device. In the above embodiment, the present invention is applied to the worm shaft 2.
However, the present invention is also applicable to the worm wheel 24 side.

[0021]

According to the present invention, in the gear box device having the casing for rotatably supporting the gear shaft and the cap member fixed to the casing for restricting the axial movement of the gear shaft, the cap member is provided. It is possible to obtain a gear box device that can be fixed to a housing without using screw connection and that has excellent fixing workability, and a method for fixing a cap member thereof.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a gear box device according to the present invention.

FIG. 2 is a sectional view showing a state before fixing a housing and a cap of the gear box device of FIG.

FIG. 3 is an exploded perspective view of the gear box device of FIG.

FIG. 4 is a systematic connection diagram showing an example of an ultrasonic welding device for welding the housing and the cap of the gear box device of FIG.

FIG. 5 is a sectional view of a housing and a cap portion showing another embodiment of the gear box device according to the present invention.

FIG. 6 is a right side view of FIG.

FIG. 7 is a cross-sectional view showing a mode in which the cap of FIGS. 5 and 6 is ultrasonically welded to the housing.

FIG. 8 is a side view of a vehicle seat track device shown as an application example of the gear box device according to the present invention.

9 is an enlarged view of a main part of FIG.

[Explanation of symbols]

10 Seat track device 11 Lower rail 12 Upper rail 13 Feed screw shaft 14 Motor unit 14a drive shaft 15 Nut body 20 Gearbox device 21 split casing 21X fixing bolt nut 22 Worm shaft (gear shaft) 23 Warm split storage recess 23a Motor unit attachment / detachment hole 23b Bearing hole 23c Warm bore Storage seat for 23d ball bearing 23d 'step 23e Receiving cylindrical part 23e 'inner peripheral edge 23f Caulking protrusion 24 warm wheels 25 Warm wheel split storage recess 26 ball bearings 26a inner ring 26b outer ring 27 Cap member 27a Inserted cylindrical portion 27b Top plate flange 27c Tapered surface 27d Caulking hole 28 washers 29 fixing nut 31 Air cylinder device 32 ultrasonic vibrating horn

Claims (6)

[Claims] 1. A gear box device comprising a casing that rotatably supports a gear shaft and a cap member that is fixed to the casing and that restricts axial movement of the gear shaft. Gearbox device characterized by being welded. 2. The gearbox device according to claim 1, wherein the gear shaft is fixed to an inner ring of a ball bearing, and the cap member sandwiches an outer ring of the ball bearing between a bearing support surface of a casing. Gearbox device to hold. 3. The gearbox device according to claim 2, wherein the cap member has an insertion tubular portion whose one end abuts on the outer ring, and a top plate flange portion located at the other end of the insertion tubular portion. The casing has a receiving tubular portion into which the insertion tubular portion of the cap member is inserted and the top plate flange portion abuts, and an inner peripheral edge of the receiving tubular portion of the casing. A gearbox device in which a portion and a boundary portion between the top plate flange portion of the cap member and the insertion tubular portion are ultrasonically welded. 4. The gearbox device according to claim 3, wherein the boundary portion includes an axis of the insertion tubular portion and a tapered surface inclined with respect to a surface orthogonal to the axis. 5. The gearbox device according to claim 2, wherein the cap member has an insertion tubular portion whose one end abuts on the outer ring, and a top plate flange portion located at the other end of the insertion tubular portion. And a plurality of caulking holes formed in the top plate flange portion, and the casing has a receiving tubular portion into which the insertion tubular portion of the cap member is inserted and the top plate flange portion abuts on an end surface thereof. And a plurality of caulking protrusions formed on the end surface of the receiving tubular portion and inserted into the caulking holes, and the caulking protrusions and the caulking holes are ultrasonically welded to each other. 6. A gear box device comprising a casing that rotatably supports a gear shaft, and a cap member that is fixed to the casing and restricts axial movement of the gear shaft, wherein the cap member is a gear of the casing. A step of applying the shaft at a position where axial movement of the cap is restricted; and ultrasonic vibration is applied to the cap member while maintaining the positional relationship between the cap member and the casing, and the cap member is generated by frictional heat generated by the ultrasonic vibration. And a casing are welded together.