JPH0594562U - Buffer gear mechanism - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a shock absorbing gear mechanism in which the phenomenon of sticking of the shock absorbing member is reduced and the shock absorbing member has high durability. [Composition] The fitting portion 21 of the cushioning member 20 has a protrusion 24.
Is formed, and the protruding portion 24 is the recessed portion 1 of the gear 10.
1 and the rotating plate 30, the buffer member 20
And a gap is formed between the recess 11 of the gear 10 and the rotary plate 30. When the shock absorbing member 20 absorbs the impact force applied to the gear 10, the fitting portion 21 of the shock absorbing member 20 is rotated by the rotating shaft 40.
Even if the cushioning member 20 expands in the direction, there is this gap.
It becomes difficult for the fitting portion 21 to press-contact with the recess 11 of the gear 10 and the rotary plate 30.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a buffer gear mechanism and is used, for example, in a speed reducer of an automobile window glass opening / closing motor.

[0002]

[Prior Art]

 Conventionally, this type of shock absorbing gear mechanism utilizes the compressive deformation of a shock absorbing member made of an elastic material to absorb the impact force generated when the rotation of the gear is suddenly stopped. For example, the speed reducer shown in FIG. 5 has a gear 51 to which a rotational torque is transmitted from a worm 62 directly connected to a motor shaft (not shown), and a fitting portion 52a which fits into a recess 51a of the gear 51. And a rotating plate 53 having an engaging piece 53a inserted into and engaging with the groove 52b of the cushioning member 52, and an oval formed at the center of the rotating plate 53. It has an output shaft 54 which is inserted into the shaped shaft insertion hole 53b and rotates integrally with the rotary plate 53. The gear 51, the buffer member 52, and the rotary plate 53 are housed in the gear housing 60. Further, the gear 51, the buffer member 52, and the rotary plate 53 are restricted from moving in the direction of the output shaft 54 by the C-shaped spring 61 engaged with the output shaft 54. At this time, the buffer member 52 is recessed into the recess 51a of the gear 51. And is in close contact with the rotary plate 53. The rotary torque transmitted from the worm 62 to the gear 51 is transmitted to the rotary plate 53 via the fitting portion 52a of the cushioning member 52, and the rotary torque rotates the output shaft 54. On the other hand, when the rotation of the output shaft 54 is abruptly restricted during the rotation operation, the rotation of the rotating plate 53 is also abruptly restricted, but the gear 51 tries to continue the rotation due to the inertial force. By the rotation of the gear 51, the fitting portion 52a is sandwiched between the concave portion 51a and the engaging piece 53a, and is compressed and deformed in the circumferential direction of the rotating plate 53 to absorb the shock due to the sudden restraint. The action of absorbing the inertial force can be similarly obtained regardless of the rotating direction of the gear 51.

[0003]

[Problems to be solved by the device]

 In the conventional impact gear mechanism described above, when absorbing a shock, the fitting part of the cushioning member rotates in the axial direction of the rotating shaft that rotates integrally with the rotating plate in accordance with the amount of compression (volume) in the circumferential direction of the rotating plate. It expands in the radial direction of the plate and is pressed into the recess of the gear and the rotating plate, causing sticking. When the restraint of the rotating shaft is released, the sticking portion is torn off, and the fitting portion returns to the original shape. Due to the repeated sticking and tearing, the cushioning member is significantly worn, and there is a problem that the durability of the cushioning member is low.

In view of the above problems, it is an object of the present invention to provide a shock-absorbing gear mechanism that reduces the phenomenon of sticking of the shock-absorbing member and that has high durability of the shock-absorbing member.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention connects a gear having a plurality of recesses formed in the circumferential direction of one side surface, a plurality of fitting portions that fit into the recesses, and an inner circumference of the fitting portion. A buffer member formed of an elastic material, which has an annular portion and a groove formed in the fitting portion from the annular portion toward the outer peripheral side, and a shaft insertion hole and an outer peripheral portion formed in the center portion. A rotary plate having a plurality of engagement pieces formed in the groove portion and inserted and engaged in the groove portion; and a rotary shaft that is fitted into the shaft insertion hole of the rotary plate and integrally rotates with the rotary plate. A technique in which a protrusion is formed on each of the surface of the fitting portion facing the recess and the surface of the fitting facing the rotary plate, and the protrusion is configured to abut the recess and the rotary plate. It adopts the objective means.

Further, in the present invention, a surface treatment layer from which the tackiness is removed may be formed on the surface of the buffer member.

[0007]

[Action]

 According to the present invention, since the technical means is provided, the protruding portion formed in the fitting portion of the cushioning member abuts the concave portion of the gear and the rotating plate, and the cushioning member and the gear A gap will be formed between the recess and the rotary plate. Then, if the rotating shaft is abruptly constrained during the rotating operation of the gear, the rotating plate that rotates integrally with the rotating shaft is also abruptly constrained, but the gear tries to continue rotating due to inertial force. Due to the rotation of the gear, the fitting portion is sandwiched between the recess of the gear and the engaging piece of the rotating plate, and is compressed and deformed in the circumferential direction of the rotating plate to absorb the shock due to the sudden restraint. At this time, even if the fitting portion expands in the axial direction of the rotating shaft and the radial direction of the rotating plate, expansion in the rotating shaft direction is absorbed by the gap, so that the fitting portion is pressed against the recess of the gear and the rotating plate. Difficult to do and sticking is reduced.

Further, when the surface treatment layer from which the adhesiveness is removed is formed on the surface of the buffer member, the sticking of the fitting portion to the recess and the rotating plate can be more reliably reduced. You can

[0009]

[Effect of the device]

 As described above, according to the buffer gear mechanism of the present invention, the expansion amount of the buffer member in the rotation axis direction can be absorbed by the gap between the fitting portion, the recess, and the rotary plate. It is possible to obtain the effect that the sticking of the fitting portion to the recess and the rotary plate can be reduced and the durability of the cushioning member can be improved.

Further, when the surface treatment layer from which the tackiness is removed is formed on the surface of the buffer member as in claim 2, the sticking of the fitting portion to the recess and the rotary plate is prevented. Since it can be more reliably reduced, the effect that the durability of the cushioning member can be further enhanced can be obtained.

[0011]

【Example】

 The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 and FIG. 2 show a speed reducer of a motor vehicle window glass opening / closing motor according to this example. Reference numeral 1 is a worm that is directly connected to a motor shaft (not shown), and 10 is a gear that meshes with the worm 1 and transmits the rotational torque of the motor shaft. , Polyacetal) is injection molded. The gear 10 is provided with three fan-shaped recesses 11 on one side in the circumferential direction, a cylindrical portion 13 having a circular hole 12 is provided in the central portion, and a gear portion 14 is provided on the outer peripheral side surface portion. There is. As shown in FIGS. 1 to 4, 20 is a cushioning member formed of an elastic material (for example, synthetic rubber), and fan-shaped fitting portions 21 that fit into the fan-shaped recesses 11 are arranged at equal intervals in the circumferential direction. The fitting portion 21 is connected to the inner circumference of the fitting portion 21 by an annular portion 22. The annular portion 22 is formed between the adjacent fitting portion 21 and a thick portion 22a formed with the same plate thickness as the fitting portion 21 at a position where the fitting portion 21 requiring strength is extended. It is composed of a thin portion 22b. The inner peripheral surface 22c of the annular portion 22 is formed to have an inner diameter that fits into the outer peripheral surface 13a of the cylindrical portion 13 of the gear 10. Further, a groove portion 23 is provided in a semi-radial direction at a position where the fitting portion 21 of each fitting portion 21 is divided into two in the circumferential direction, from the annular portion 22 toward the outer peripheral side. The groove portion 23 penetrates the fitting portion 21 in the plate thickness direction, and has a wide portion 23a whose width is widened in the circumferential direction at the end portion on the annular portion 22 side. Reference numeral 24 denotes a columnar protruding portion, which is provided at two locations (one on each side of the groove portion 23) on the surface D of the fitting portion 21 facing the recess 11, and the fitting portion 21 will be described later. The surface E facing the rotating plate 30 is provided in the same number in the circumferential direction at the same position as the projecting portion 24 of the surface D, and is provided at 12 positions in the buffer member 20 as a whole. The height H and the width W of the protruding portion 24 are set to predetermined values according to the conditions described later. The cushioning member 20 is integrally formed with a fitting portion 21, an annular portion 22, and a protruding portion 24. Reference numeral 30 is a rotary plate formed by press-forming a steel plate, and has three engaging pieces 31 that are inserted and engaged in the groove 23, and an oval shaft insertion hole 32 is provided in the center. Reference numeral 40 denotes a rotation shaft, which is inserted into the oval shaft insertion hole 32 of the rotation plate 30 and serves as a rotation stopper. The oblong column portion 41, the column portion 42, and the prism having a width larger than the outer diameter of the column portion 42. The oval column 41 is provided with an engaging groove 44 for engaging with the C-shaped spring 2 at each of the curved surfaces facing each other. Reference numeral 3 denotes a gear housing having a gear housing 3a for housing the gear 10, the buffer member 20, and the rotary plate 30. The gear housing 3a has a shaft through hole 3b at the center thereof, and the gear 10 has a circular hole 12a. A cylindrical portion 3c to be inserted into is provided. Then, as shown in FIG. 2, the gear 10, the cushioning member 20, and the rotary plate 30 are housed in the gear housing 3a and inserted into the shaft through hole 3b. The rotary plate 30 is inserted into the oval shaft insertion hole 32 of the plate 30 and rotates together with the rotary shaft 40. Further, the C-shaped spring 2 is engaged with the engagement groove 44, and movement of the gear 10, the cushioning member 20, and the rotary plate 30 in the direction of the rotary shaft 40 is restricted. At this time, the protruding portion 24 abuts on the concave portion 11 and the rotary plate 30, a gap F is formed between the fitting portion 21 and the concave portion 11, and a gap G is formed between the fitting portion 21 and the rotary plate 30. It

Next, the operation of this embodiment having the above structure will be described. If the window glass stops at the upper and lower ends of the opening and closing during the rotational operation of the gear 10, and the rotary shaft 40 is suddenly restrained, the rotary plate 30 that rotates together with the rotary shaft 40 is also suddenly restrained. 10 tries to continue rotation by the inertial force generated by the rotation torque of the motor shaft. Due to the rotation of the gear 10, the fitting portion 21 of the cushioning member 20 is sandwiched between the recess 11 of the gear 10 and the engaging piece 31 of the rotating plate 30, and is compressed and deformed in the circumferential direction of the rotating plate 30 to cause a sudden change. It absorbs the impact of the binding and prevents the gear portion 14 of the gear 10 from being damaged. At this time, the fitting portion 21 expands in the direction of the rotating shaft 40 and in the radial direction of the rotating plate 30, and this expansion depends on the amount (volume) of compressive deformation due to the inertial force generated by the rotating torque of the motor shaft. Since this occurs, the amount (volume) of compressive deformation is obtained in advance by experiments, etc., and the height of the protruding portion 24 is set so that the sum of the volume of the gap F and the volume of the gap G is larger than the amount (volume). Set H. In the case of this example, the rotation torque of the motor shaft is 40 to 160 kgfcm in terms of the rotation torque of the output shaft 40, and the height H of the protruding portion 24 is set to 0.7 mm. Further, the width W of the protruding portion 24 is set to be larger than the height H in order to prevent the protruding portion 24 from buckling due to the expansion when it is pressed against the recess 11 and the rotating plate 30. Has been done. In the case of this example, it is set to 2 mm. As described above, the gap F is formed between the fitting portion 21 and the recess 11 of this example, and the gap G is formed between the fitting portion 21 and the rotating plate 30. Since the fitting portion 21 absorbs the expansion in the direction of the rotating shaft 40, the fitting portion 21 is less likely to be pressed against the recess 11 and the rotary plate 30, and sticking is reduced. Therefore, the wear of the cushioning member 20 can be reduced, and the durability of the cushioning member 20 can be enhanced. Further, particularly in this embodiment, since the wide portion 23a is provided at the end of the groove portion 23 of the fitting portion 21 on the annular portion 22 side, the end surface of the engaging piece 31 of the rotary plate 30 on the shaft insertion hole 32 side. It is possible to prevent the fitting portion 21 from being damaged by a press burr or the like generated at the time of press molding on this end surface.

Further, when a surface treatment layer from which tackiness has been removed is formed by chlorine treatment on the surface of the cushioning member 20 shown in FIGS. 3 and 4, expansion of the fitting plate 21 in the radial direction of the rotary plate 30 is prevented. Also, since the sticking can be reduced, the sticking of the fitting portion 21 to the recess 11 and the rotary plate 30 can be more reliably reduced, and the durability of the cushioning member can be further enhanced.

Although the speed reducer of the motor vehicle window glass opening / closing motor is used in the above-mentioned one embodiment, the present invention is not limited to this, and a gear mechanism having a buffer structure can be used in a similar manner. It is possible. In addition, in the above-described embodiment, the recesses 11 of the gear 10 are fan-shaped at three positions, but the present invention is not limited to this, and may be square or circular, and may not be three. Therefore, the shape of the fitting portion 21 of the cushioning member 20 that fits into the recess 11 may also be a quadrangle or a circle, and need not be three. Further, although the protruding portion 24 of the fitting portion 21 is cylindrical, it is not limited to the cylindrical shape, and may be a prism, a truncated cone, or a truncated pyramid. Further, although the example in which the surface treatment layer of the cushioning member 20 is formed by chlorine treatment is used, it is not limited to chlorine treatment, and any material that removes tackiness may be used, for example, molybdenum coating. However, it may be Teflon processed. Further, although the example in which the cushioning member 20 is integrally formed is used, the structure is not limited to the integral structure, and for example, the thin portion 22b may be removed and the cushioning member 20 may be formed in a divided structure. (The fitting portion 21, the thick portion 22a, and the protruding portion 24 are integrated)

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a buffer gear mechanism according to the present invention.

FIG. 2 is a sectional view showing an embodiment of a buffer gear mechanism according to the present invention.

FIG. 3 is a plan view of a cushioning member according to an embodiment of the present invention.

FIG. 4 is a front view of a cushioning member according to an embodiment of the present invention.

FIG. 5 is a perspective view showing a conventional buffer gear mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Gear 11 Recess 20 Buffer member 21 Fitting part 22 Annular part 23 Groove part 24 Projecting part 30 Rotating plate 31 Engaging piece 32 Shaft inserting hole 40 Rotating shaft

Claims (2)

[Scope of utility model registration request] 1. A gear having a plurality of recesses formed in a circumferential direction on one side surface, a plurality of fitting portions that fit into the recesses, an annular portion that connects the inner circumference of the fitting portion, and the fitting. Has a groove portion formed from the annular portion toward the outer peripheral side, a buffer member formed of an elastic material, a shaft insertion hole formed in the central portion and an insertion member formed in the outer peripheral portion. A rotary plate having a plurality of engaging pieces to be fitted together, and a rotary shaft that is inserted into the shaft insertion hole of the rotary plate and integrally rotates with the rotary plate, and faces the concave portion of the fitting portion. A cushioning gear mechanism, characterized in that a protruding portion is formed on each of the surface that faces the rotating plate and the surface that faces the rotating plate, and the protruding portion contacts the recess and the rotating plate. 2. The shock-absorbing gear mechanism according to claim 1, wherein a surface-treated layer whose adhesiveness is removed is formed on the surface of the shock-absorbing member.