JP2007315555A - Differential device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To change initial torque imparted to a friction clutch in a state that a pressurizing spring is arranged between pressure rings in a differential device having a differential limit function. <P>SOLUTION: Spring holes 21 and 22 wherein the pressurizing spring 14 is arranged along an axle direction are formed at confronting surfaces of left and right pressure rings 2 and 3, a spring pushing body 26 is arranged between the inner wall surface 21a of one of the spring hole 21 and the end of the pressurizing spring 14 so as to be movable in the axle direction. When a spring force adjusting member 29 having a flange 32 fitted into a counterbored hole 23 formed at the pressure ring 2 is screwed, a differential rod 27 of the spring pushing body 26 is pushed by the flange 32, and the pressurizing spring 14 is compressed, and an initial set length is reduced. Therefore, the initial set length is switched by the attachment/detachment of the spring force adjustment member 29, and the initial torque is changed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a differential device (hereinafter referred to as LSD) having a differential limiting function called a limited slip differential gear or the like in which a limited slip differential case is provided in a differential carrier, and particularly between a pair of left and right pressure rings. The present invention relates to a differential device that can adjust a spring force of a pressurizing spring provided.

  When a driving force is transmitted and a limited slip differential case (hereinafter simply referred to as a case) rotates, the LSD has a pair of pressure rings that are opposed to each other in the case, and the LSD is located between the case and each pressure ring. Rotational force is transmitted from the case via a multi-plate friction clutch disposed in the casing. In addition, cross-shaped pinion shafts are disposed at the opposing portions of the pair of pressure rings, and pinion gears pivotally attached to the four pinion shafts mesh with the left and right side gears, respectively. Left and right axles are attached to the left and right side gears. Although the multi-plate friction clutch is movable in the axial direction, a part of the multi-plate friction clutch rotates integrally with the case, and the other part rotates integrally with the side gear.

  Cam groove portions that engage with cam portions formed on the pinion shafts are formed on the outer peripheral portions of the pair of pressure rings, and the pair of pressure rings are formed by a cam component mechanism that includes the cam portions and the cam groove portions. The pressure ring moves outward in the axial direction and presses the multi-plate friction clutch to increase the differential limiting force. The mechanism for increasing the pressing force with respect to the multi-plate friction clutch is that when the drive torque increases, the drive torque applied to the pair of pressure rings also increases, and the cam surface of the cam groove portion is obtained in contact with the cam portion in the axial direction. By increasing the component force.

  In such an LSD, a spring is disposed between a pair of left and right pressure rings, the pair of left and right pressure rings are urged outward in the axial direction, and the left and right multi-plate friction clutches are applied and pressure-bonded. It has been proposed (cited documents 1, 2, 3).

  By applying pressure to the left and right multi-plate friction clutches, a certain amount of torque (initial torque) can be transmitted directly from the side gears to the drive wheels via the multi-plate friction clutch.

  Since this initial torque affects the effectiveness of differential limitation, a proposal has been made that the initial torque can be adjusted (Cited Document 1).

The adjustment of the initial torque disclosed in the cited document 1 is performed by exchanging the pressurizing spring with one having a different spring constant or by increasing or decreasing the number of the pressurizing springs. The pressure spring replacement operation can be performed through a work hole formed in the case without disassembling the parts in the case.
JP 2001-323987 A JP 2000-104807 A JP 09-004696 A

  In the pressurized spring exchange type LSD described in Patent Document 1 described above, an operation of taking out the pressurized spring from between the pair of left and right pressure rings and another pressurized spring between the pair of left and right pressure rings. Plugging work is required.

  Although such replacement work can simplify the replacement work in that it does not require disassembly of the LSD, it is desired to further shorten the work time.

  The object of the present invention is made in view of such a viewpoint, and the pressurization can be adjusted in a state where the pressurization spring is disposed between the pair of left and right pressure rings, so that the time required for the pressurization adjustment work is shortened. It is an object of the present invention to provide a differential device having a differential limiting function.

According to a first configuration of a differential device that realizes the object of the present invention, the left and right pressure rings are disposed opposite to each other in a differential case that rotates when a driving force is transmitted from a driving force source. Left and right side gears connected to the left and right axles by arranging a plurality of pressurizing springs along the circumferential direction between the opposing surfaces of the left and right sides, applying pressure to the left and right multi-plate friction clutches via the left and right pressure rings In the differential device having an operation limiting function for applying an initial torque via each multi-plate friction clutch, the pressurizing springs formed respectively along the axle direction are disposed on the opposing surfaces of the left and right pressure rings. A spring movably disposed in the axial direction between the spring hole, the back wall surface of one of the spring holes, and one end of the pressurizing spring. A ring pusher and a pressure ring in which any one of the spring holes is formed are mounted so as to be screwable from the outside in the radial direction, and interferes with the spring pusher and resists the spring force of the pressurizing spring. A spring force adjusting member for moving the spring pusher, and a pressurizing spring device comprising:
The pressurizing spring device is characterized in that the initial torque for the multi-plate friction clutch can be switched depending on whether or not the spring force adjusting member is attached.

  According to a second configuration of the differential device that realizes the object of the present invention, as set forth in claim 2, in the first configuration described above, the pressurizing spring device includes a back wall surface of one of the spring holes. The upper part of the spring force adjusting member formed on the outer periphery of the pressure ring is adjacent to the recess, and the spring pusher passes through the inner wall surface of one of the spring holes into the recess. And an upper portion of the spring force adjusting member moves the operating rod toward the other spring hole in a state where the spring force adjusting member is screwed.

  According to a third configuration for realizing the object of the present invention, according to any one of the above-described configurations, the differential case may correspond to a portion where the spring force adjusting member is screwed. A working hole is formed.

  According to a fourth configuration for realizing the object of the present invention, in any one of the above-described configurations, the differential carrier that accommodates the differential case has a work hole formed in the differential case. The working hole is formed correspondingly.

  According to a fifth configuration for realizing the object of the present invention, as set forth in claim 5, in any one of the above-described configurations, the spring force adjusting member is formed by either one of the spring holes. On the other hand, in the non-mounted state, the pressurizing spring is set to an initial length that does not apply pressurization.

  According to the present invention, depending on whether or not the spring force adjusting member is screwed into the pressure ring, the initial set length of the pressurizing spring is divided into two stages, that is, a long and short, with the pressurizing spring being disposed between the left and right pressure rings. Thus, the initial torque applied to the left and right multi-plate friction clutches can be adjusted via the left and right pressure rings.

  Further, since this adjustment work can be performed through a work hole formed in the differential case, the adjustment work can be completed in a short time.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

  1 is a top view of a pressurizing spring device in a differential device showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional view taken along the line AA of FIG. 1, and FIG. 3 is a differential device showing an embodiment of the present invention. FIG. 4 is a view showing an arrangement state of pressurizing springs of the differential device shown in FIG.

  First, the overall configuration of a differential apparatus (LSD) having a differential limiting function will be described with reference to FIGS.

  In the LSD of this embodiment, a ring gear 12 is fixed to a differential case (hereinafter abbreviated as a case) 1, and a pinion gear 13 to which the rotation of the engine is transmitted meshes with the ring gear 12 to drive from the engine (motor). The case 1 is rotated by the force. A pair of pressure rings 2 and 3 are accommodated in the case 1 so as to be movable in the axial direction of the axles 10 and 11 of the drive wheels. A pinion shaft (formed in a cross shape) 4 is disposed between the pair of pressure rings 2 and 3, and a pinion gear 5 is rotatably attached to the tip of each shaft 4. A pair of side gears 6 and 7 are meshed with each other so as to be sandwiched from both the left and right sides. The left and right axles 10 and 11 are splined to the pair of left and right side gears 6 and 7, respectively, and rotate integrally.

  Multi-plate friction clutches 8 and 9 are disposed between the left and right pressure rings 2 and 3 and the left and right inner side walls of the case 1, respectively. The multi-plate friction clutches 8 and 9 are, for example, odd-numbered friction clutch plates. Is attached to the case 1 so as to be axially movable and non-rotatable, and even-numbered friction clutch plates are attached to the side gears 6 and 7 so as to be axially movable and non-rotatable.

  Further, a pressurizing spring 14 is disposed between the left and right pressure rings 2 and 3, and the left and right pressure rings 2 and 3 are pressed so that the respective friction clutch plates of the left and right multi-plate friction clutches 8 and 9 are preliminarily provided. Crimping is performed at a predetermined pressure.

  In the present embodiment, the cam component force mechanism operates differential limiting during forward driving (ON), and when the driving force is transmitted from the driving wheel side using the engine brake during forward driving, differential limiting is performed. A configuration in which the function is turned off is adopted.

  In order to obtain this configuration, the pinion shaft 4 is provided with a cam portion 4A that constitutes a part of the cam component mechanism using the shaft shape of the pinion shaft, at a radially outer position than the pinion gear 5. The cam portion 4A has a substantially D-shaped axial cross section having a linear end face 4AA and an arcuate curved surface 4AB that are parallel to each other along the axle direction.

  When the forward drive force F is transmitted from the engine side to the LSD, the drive force is transmitted from the case 1 to the multi-plate friction clutches 8 and 9 to the pressure rings 2 and 3. As a result, the pressure rings 8 and 9 press the multi-plate friction clutches 8 and 9 by the action of the cam component force mechanism to add the frictional force to the initial torque by the pressurizing spring 14 and further increase the frictional force. Is directly transmitted from the multi-plate friction clutches 8 and 9 to the side gears 6 and 7. If the foot is released from the accelerator pedal (OFF) during forward travel, the engine speed decreases and the drive torque decreases, causing the multi-plate friction clutches 8 and 9 to be pressed with the initial torque, and the pressure rings 3 and 4 → The transmission path of the driving force is connected from the pinion shaft 4 to the pinion 5 to the side gears 6 and 7, and the differential function between the pinion 5 and the side gears 6 and 7 is turned ON.

  Next, the configuration of the pressurizing spring device will be described with reference to FIGS. In the description, the left-right direction refers to the left-right direction of the drive wheels when attached to the vehicle.

  In the present embodiment, the pair of left and right pressure rings 2 and 3 are formed in a cylindrical shape, and a plurality of spring holes 21 and 22 into which the pressurizing springs 14 are inserted are formed in the circumferential direction on opposite end faces. . In order to dispose the pressurizing spring 14 at the outer end positions of the pair of left and right pressure rings 2 and 3 as much as possible, a part in the radial direction of the spring holes 21 and 22 is the outer end edge of the pair of left and right pressure rings 2 and 3. The spring holes 21 and 22 are open along the axial direction.

  A countersink hole 23 is formed in the right pressure ring 2 adjacent to the back wall surface 21 a of the spring hole 21, and a screw hole 24 is formed at the center of the countersink hole 23.

  A communication hole 25 that connects the spring hole 21 and the counterbore 23 is formed in the inner wall surface 21 a of the spring hole 21.

  An operating rod 27 of a spring pusher 26 passes through the communication hole 25, and the spring pusher 26 is moved outwardly from the outer end side of a spring seat 28 disposed in the spring hole 21. Is extended.

  In the present embodiment, the pressurizing spring 14 disposed in the spring hole 21 has one end abutting against the back wall surface 22a of the spring hole 22 and the other end abutting against the spring seat 28 of the spring pusher 26. The spring pusher 26 is biased outward in the axial direction by the spring force of the spring 14.

  A screw portion 30 of a spring force adjusting member 29 formed in a bolt shape is screwed into the screw hole 24 of the counterbore 24, and the hexagonal head 31 is turned with a hexagon wrench or the like, whereby a spring force adjusting member is obtained. 29 is screwed.

  In the spring force adjusting member 29, a disk-shaped flange portion 32 is formed between the screw portion 30 and the head portion 31, and the flange portion 32 has a diameter larger than that of the screw portion 30. Further, the joint 33 between the screw portion 30 and the flange portion 32 is formed in a tapered surface.

  As shown in FIG. 2A, when the spring force adjusting member 29 is not screwed into the screw hole 24, the spring seat 28 of the spring pusher 26 is in a state where the pressurizing spring 14 is disposed in the spring holes 21 and 22. Abutting on the inner wall surface 21a of the spring hole 21, the spring force is weak, that is, the initial torque is small. At this time, the actuating rod 27 faces the spring seat 23, and the tip of the actuating rod 27 exists inside the collar portion 32 in a state where the spring force adjusting member 29 is screwed into the screw hole 24. Then, the edge of the screw hole 24 is reached.

  Therefore, as shown in FIG. 2B, when the spring force adjusting member 29 is screwed into the screw hole 24, the tip of the operating rod 27 can be prevented from interfering with the screw portion 30 of the spring force adjusting member 29. Since the tip of the actuating rod 27 has a tapered surface, even if the tip of the actuating rod 27 interferes with the threaded portion 30 of the spring force adjusting member 29 due to manufacturing accuracy, the screw of the spring force adjusting member 29 The part 30 is smoothly screwed into the screw hole 24.

  When the spring force adjusting member 29 starts to be screwed into the screw hole 24, the tip of the operating rod 27 comes into contact with the joint 33 formed on the tapered surface, and the operating rod 27 gradually resists the spring force of the pressurizing spring 14. Then, the spring force of the pressurizing spring 14 is increased. Further, when the spring force adjusting member 29 is screwed in, as shown in FIG. 2C, the operating rod 27 smoothly contacts the flange 32 through the joint 33, and the spring pusher 26 is applied to the pressurizing spring 14. Press to set to a predetermined length. Since the spring force when set to the predetermined length is shorter than the length when the spring force adjusting member 29 shown in FIG. 2A is not set, the spring force when the spring force adjusting member 29 is set. Will grow.

  Therefore, the initial torque for the multi-plate friction clutches 8 and 9 can be switched between a low torque state where the spring force adjusting member 29 is not screwed into the screw hole 24 and a high torque state where the spring force adjusting member 29 is screwed into the screw hole 24. become.

  In the present embodiment, the screwing operation of the spring force adjusting member 29 is performed through the work holes 34 formed in the case 1 corresponding to the screw holes 24. The working hole 34 may have a long hole shape extending in the axle direction that covers not only the screw hole 24 but also the spring holes 21 and 22 at the same time. In this case, the replacement work of the pressurizing spring 14 can be performed through the working hole 34.

  Of course, if a work hole is formed corresponding to the work hole 34 in a differential carrier (not shown) that accommodates the case 1, the spring force is adjusted from the work hole of the differential carrier through the work hole 34 of the case 1. Since the member 29 can be screwed and the pressurizing spring 14 can be replaced, the above-described operation can be performed without removing the differential device from the vehicle body. Note that the number of work holes formed in the differential carrier may be one, and the case 1 rotates by slowly turning the wheel, for example, with the vehicle body jacked up, so that each work hole 34 is aligned with the work hole of the differential carrier. You can perform necessary work together.

  In the above-described embodiment, the pressure spring 14 applies pressure to the left and right pressure rings 2 and 3 when the differential device is not driven, but the spring force adjusting member 29 is connected to the screw hole 24 of the pressure ring 2. The spring force that the pressurizing spring 14 applies to the left and right pressure rings in a state where the pressure spring 14 is removed from the pressure may be zero. In this case, by making the opening width of the spring holes 21 and 22 narrower than the width of the pressurizing spring 14, the pressurizing spring 14 in a free state does not come out of the spring holes 21 and 22 radially outward. .

  Therefore, the initial torque for the multi-plate friction clutches 8 and 9 includes a low torque state including zero torque where the spring force adjusting member 29 is not screwed into the screw hole 24, and a high torque state where the spring force adjusting member 29 is screwed into the screw hole 24. Can be switched to.

  Further, the initial torque in the high torque state can be arbitrarily changed by changing the diameter of the flange portion 32 of the spring force adjusting member 29.

  Further, a plurality of pressurizing springs 14 can be arranged between the left and right pressure rings 2 and 3 in the circumferential direction. By appropriately selecting the number of these pressurizing springs, the spring constant, etc., the initial torque can be reduced. The setting range can be expanded.

The figure which looked at a part of differential apparatus which shows embodiment of this invention from upper direction. 1. It is an AA arrow sectional drawing of FIG. 1, (a) is the state which is not mounting | wearing with a spring force adjustment member, (b) is the state immediately before screwing a spring force adjustment member in a screw hole, (c) is spring force. The state which screwed the adjustment member is shown. The longitudinal cross-sectional view of the whole structure of the differential apparatus of FIG. The figure which shows the arrangement | positioning state of the pressurization spring of the differential apparatus shown in FIG.

Explanation of symbols

1 Differential case (case)
1a Working hole 2, 3 Pressure ring 4 Pinion shaft 4A Cam part 4AA Straight end face 4AB Curved surface 5 Pinion gears 6, 7 Side gear 8, 9 Multi-plate friction clutch 10, 11 Axle 12 Ring gear 13 Pinion gear 14 Pressing spring 21, 22 Spring hole 21a, 22b Deep wall surface 23 Seat feeding hole 24 Screw hole 25 Communication hole 26 Spring pusher 27 Actuating rod 28 Spring seat 29 Spring force adjusting member 30 Screw part 31 Head part 32 Hook part 33 Joint 34 Working hole

Claims (5)

A plurality of pressurizing springs are arranged along the circumferential direction between the opposing surfaces of the left and right pressure rings arranged in a differential case that rotates when a driving force is transmitted from a driving force source, and left and right multi-plate friction In a differential apparatus having an operation limiting function that applies pressure to the clutch via left and right pressure rings and applies initial torque to the left and right side gears connected to the left and right axles via the multi-plate friction clutches,
A spring hole in which the pressurizing springs are formed on the opposing surfaces of the left and right pressure rings along the axle direction, respectively, and between a back wall surface of one of the spring holes and one end of the pressurizing spring. A spring pusher that is freely movable in the axial direction, and a pressure ring in which any one of the spring holes is formed so as to be screwable from the outside in the radial direction to interfere with the spring pusher, A spring force adjusting member for moving the spring pusher against the spring force of the pressure spring, and a pressurizing spring device comprising:
The differential spring device is characterized in that the initial torque for the multi-plate friction clutch can be switched depending on whether or not the spring force adjusting member is attached.   The pressurizing spring device has a recess into which an upper portion of the spring force adjusting member formed on the outer peripheral portion of the pressure ring is adjacent to the inner wall surface of the one of the spring holes, and the spring pusher has the An operating rod that penetrates the inner wall surface of one of the spring holes and faces into the recess, and the upper portion of the spring force adjusting member is screwed into the one of the other while the spring force adjusting member is screwed The differential device according to claim 1, wherein the differential device is moved toward the spring hole.   The differential apparatus according to claim 1, wherein a work hole is formed in each of the differential cases so as to correspond to locations where the spring force adjusting member is screwed.   The differential apparatus according to any one of claims 1 to 3, wherein a work hole is formed in the differential carrier that accommodates the differential case so as to correspond to the work hole formed in the differential case. When the spring force adjusting member is not attached to the pressure ring in which any one of the spring holes is formed, the pressurizing spring is set to an initial length that does not apply pressurization. The differential apparatus in any one of Claim 1 to 4.

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