JPH0620954U - Gear squeal prevention mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to a gear squeal preventing mechanism used in a transfer device or the like, and an object thereof is to prevent generation of a gear squeal when switching between high speed and low speed. [Structure] A check ball that is inserted into a check groove of a shift rod that switches between high speed and low speed, a rod that has a tapered portion that stops rotation of the main gear and a large diameter portion on the rear end side, and a large diameter The check spring is interposed between the check part and the check ball, and the return spring is interposed between the large diameter part and the ring member fixed to the case.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gear squeal prevention mechanism used in a transfer device or the like.

[0002]

[Prior art]

 As a conventional transfer device, for example, there is one shown in FIG. In FIG. 3, reference numeral 1 denotes a transfer device for a four-wheel drive vehicle equipped with an automatic transmission, which has a rear case 2 and a front case 3. Reference numeral 4 is a main drive shaft through which the driving force from the engine is transmitted by being coupled to the output shaft of the transmission by a spline through an automatic transmission, and 5 is a main shaft extending to the propeller shaft side. The main drive shaft 4 is integrally formed with a main drive gear 7 that meshes with one counter gear 6A, and the other counter gear 6B is a low speed that is relatively rotatably mounted on the main shaft 5 via a needle bearing. It meshes with the gear 8 and the rotational force of the main drive shaft 4 is transmitted to the low speed gear 8 via the main drive gear 7 and the counter gears 6A and 6B. Reference numeral 9 denotes a hub fitted to the main shaft 5 by a spline, and a coupling sleeve 10 is slidably engaged with the hub.

The main shaft 5 is rotatably supported by the cases 2 and 3 via bearings 11 and 12. Reference numeral 13 is a hub for switching between 2WD and 4WD, and the hub 13 is formed integrally with the main shaft 5. Reference numeral 14 is a drive sprocket, and the drive sprocket 14 is rotatably supported by the main shaft 5 via a needle bearing.

A clutch gear 15 is formed integrally with the drive sprocket 14, and a coupling sleeve 16 is meshed with the clutch gear 15 and the hub 13. A chain 19 is installed between the drive sprocket 14 and the driven sprocket 18 integrally formed on the front drive shaft 17, and is rotatably supported by the bearings 20 and 21 on the cases 2 and 3 via the chain 19. The rotational force of the engine is transmitted to the front drive shaft 17 that has been set.

Rotational force is input to the front axle via the front drive shaft 17, the propeller shaft, and the differential gear, and a 4WD traveling state is set.

[0006]

[Problems to be solved by the device]

 However, in such a conventional transfer device, switching between high speed and low speed is operated while the vehicle is stopped, but friction resistance against drag rotation of the input shaft of the automatic transmission is used. The output shaft rotates dragging, and the main drive shaft of the transfer device connected to it also drags. In particular, there was a problem that gear noise occurred when shifting from high speed ← → neutral ← → low speed at low temperatures where there was a large amount of drag.

The present invention has been made in view of the above conventional problems, and an object thereof is to prevent the occurrence of gear squeal at the time of switching between high speed and low speed.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention has a check ball inserted into a check groove of a shift rod for switching between high speed and low speed, and a taper portion movably accommodated in a case to stop rotation of a main gear. A rod having a large diameter portion on the front end side on the rear end side, a check spring interposed between the large diameter portion and the check ball, and an insertion between the large diameter portion and a ring member fixed to the case. It is equipped with a return spring.

[0009]

[Action]

 When switching the shift rod from high speed to low speed or from low speed to high speed, when the check ball moves from the check groove to the neutral position, the rod is pressed by the check spring and moves axially against the return spring. The tapered portion of the rod contacts the main gear and stops the rotation of the main gear.

When the rotation of the main gear stops and the shift to the high speed or the low speed is completed, the check ball enters the check groove of the shift rod, and at the same time, the rod returns to its original position by the return spring and the check spring, and the braking force is increased. Becomes zero. Thus, by utilizing the movement of the check ball, it is possible to prevent the occurrence of gear noise.

[0011]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the present invention. First, the configuration will be described. In FIG. 1, reference numeral 31 is a case of a transfer device. In the case 31, a shift rod 32 for switching between high speed (H) and low speed (L) and a four-wheel drive (4WD)- A shift rod 33 for switching between two-wheel drive (2WD) is slidably supported.

A lock pin 34 is provided between the shift rod 32 and the shift rod 33, and both lock rods 32 and 33 are locked by the lock pin 34. A check ball 36 is inserted in a check groove 35 for 4WD or 2WD of the shift rod 33, and a check spring 38 is interposed between the check ball 36 and the bolt 37.

As shown in FIG. 2, the shift rod 32 is provided with a high speed check groove 39 and a low speed check groove 40, respectively, and the space between the check grooves 39 and 40 is in a neutral position. The shift rod 32 slides in the direction indicated by arrow A. Reference numeral 41 is a check ball fitted in the check grooves 39, 40, and the check ball 41 is stored in a storage hole 42 formed in the case 31.

Reference numeral 43 denotes a rod movably housed in the housing hole 42. The rod 43 has a taper portion 44 on the front end side and a large diameter portion 45 on the rear end side. A check spring 46 is interposed between the check ball 41 and the large diameter portion 45 of the rod 43, and a return spring 48 is interposed between the bush (ring member) 49 fixed to the case 31 and the large diameter portion 45. Has been done. Further, the bush 49 slidably supports the rod 43.

The taper portion 44 of the rod 43 has an angle of 20 degrees or more, and its center line is made to coincide with the tangent line of the main gear (main drive gear) 50 rotating in the direction indicated by the arrow C. The material of the rod 43 is the same carburized steel as the main gear 50. The rod 43 is balanced by a check spring 46 and a return spring 48. The rod 43 has a different spring constant due to the movement of the check ball 41, and moves in the direction indicated by the arrow B in FIG. If the spring constant of the return spring 48 is KB and the spring constant of the check spring 46 is KA, it is set such that KB ≧ KA. When the rod 43 does not move, the gap between the tapered portion 44 of the rod 43 and the main gear 50 is maintained at 0.5 to 1 mm. Incidentally, 53 and 54 are plugs.

Next, the operation will be described. When the shift rod 32 is operated to switch from high speed to low speed or from low speed to high speed, the check ball 41 moves from the check groove 39 or the check groove 40 to the neutral position by 2 to 3 mm. At this time, since the relation between the spring constant KA of the check spring 46 and the spring constant KB of the return spring 48 is KB ≧ KA, the rod 43 moves to the right in FIG. 1, and the taper portion 44 of the rod 43 moves to the main gear 50. Contact with. As a result, the rotation of the main gear 50 can be stopped. As a result, the generation of gear noise can be prevented.

When the rotation of the main gear 50 stops, the shift to the high speed or the low speed is completed, and the check ball 41 falls into the check groove 39 or the check groove 40, the rod 43 is returned to the original state by the return spring 48 and the check spring 46. Returning to the position, the braking force on the main gear 50 becomes zero. Although the present invention has been described for the case of a high speed / low speed switching mechanism of the transfer device, it can be applied to non-synchronized fast and reverse transmissions.

[0018]

[Effect of device]

 As described above, according to the present invention, the movement of the check ball moves the rod having the taper portion to bring it into contact with the main gear and stop the rotation of the main gear. It is possible to prevent gear noise when switching to a low speed.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

[Fig. 2] Operation explanatory diagram

FIG. 3 is a diagram showing a conventional transfer device.

[Explanation of symbols]

 31: Case 32: Shift rod (for H-L switching) 33: Shift rod (for 4WD-2WD switching) 34: Lock pin 35: Check groove 36: Check ball 37: Bolt 38: Check spring 39, 40: Check groove 41: Check ball 42: Storage hole 43: Rod 44: Tapered portion 45: Large diameter portion 46: Check spring 48: Return spring 49: Bush (ring member) 50: Main gear 53: Plug 54: Plug

Claims (1)

[Scope of utility model registration request] 1. A check ball fitted into a check groove of a shift rod for switching between high speed and low speed, and a taper portion movably accommodated in a case for stopping rotation of a main gear on a front end side and a large diameter portion. A check spring inserted between the large diameter portion and the check ball, and a return spring inserted between the large diameter portion and a ring member fixed to the case. Gear squeal prevention mechanism characterized by that.