JPH0516447U - Deflot device - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the diff lock operation force by simple modification of the operation mechanism. [Structure] Claw portion 9 on the side of differential case 20 and front axle 8
A diff lock device A including a diff lock mechanism 11 that is engaged and disengaged with a claw clutch member 10 that is spline-fitted to the spline, and a shift lock device A that slides the claw clutch member 10 is provided. The tip portion 18b is a single cantilevered rod that engages with the circumferential groove 10a of the pawl clutch member 10 at only one location, and the tip portion 18b and the side wall surface of the pawl portion in the circumferential groove 10a are in contact with each other. The pressing surface 18c is formed on the tip portion 18b by cutting so as to be in this state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a diff lock device suitable for a work vehicle such as a lawn mower or a tractor, and more specifically, a claw portion formed on a side end portion of a diff case and a spline externally fitted to an output diff shaft slidably in an axial direction. The present invention relates to a diff lock device including a defloc mechanism which is engaged and disengaged with an annular claw clutch member and an operating mechanism thereof.

[0002]

[Prior Art]

 As shown in FIG. 4, this type of diff lock device rotates the operating shaft 15 by engaging an engaging pin 16 inserted into and fixed to the operating shaft 15 and an inclined groove 14 formed in an annular operating body 17. The operating body 17 is configured to slide in the axial direction by a dynamic operation, and the shift fork 18 attached to the operating body 17 is passed through the operating hole 21 formed in the case 2 to thereby output the output differential shaft 8 By engaging the claw clutch member 10 with the claw portion 9 formed at the side end of the differential case 20, the claw clutch member 10 is engaged with the circumferential groove 10a of the annular claw clutch member 10 which is spline-fitted to the. It was designed to switch between the differential state and the differential lock state.

[0003]

[Problems to be solved by the device]

 In the above-mentioned conventional technology, there is a cost merit that the shift fork can be formed by a simple round bar, but since the contact state with the claw clutch member comes into line contact, this operating pin is in a cantilevered state on the operating body. On the other hand, when pressing on the diff lock side, where the operating force is large, the operating force sometimes felt heavy because of a tight contact with the shaft support. An object of the present invention is to reduce the diff lock operation force by simply modifying the operation mechanism.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is achieved by engaging and disengaging a claw portion formed at a side end portion of a differential case and an annular claw clutch member which is spline-fitted to an output diff shaft so as to be slidable in an axial direction. In addition to the above-mentioned diff lock mechanism, an operating mechanism for opening and closing the diff lock mechanism is provided, and a shift fork for slidingly operating the pawl clutch member of this operating mechanism is formed at the tip of the shift fork on the outer peripheral portion of the pawl clutch member. It is composed of a single cantilevered round bar that engages in only one place in the circumferential groove, and the tip part is attached so that the tip part and the side wall surface of the claw part in the circumferential groove are in face-to-face contact. It is characterized in that the pressing surface is formed by cutting.

[0005]

[Action]

 According to this, the shift fork and the pawl clutch member come into face-to-face contact with each other when operating on the diff lock side, which requires a relatively large operating force, so that the pawl is at least laterally relative to the longitudinal direction of the shift fork. It is possible to eliminate the phenomenon that the clutch member is jammed, and the operating force is reduced accordingly. Also, since the shift fork has a simple structure in which a round bar is cut, the shift fork can be constructed at a lower cost than, for example, a shift fork having a surface contact and required strength by forging. Become.

[0006]

[Effect of the device]

 Therefore, it was possible to provide a diff lock device that can be expected to be operated lighter than before by reducing the operating force by modifying the shift fork, which is economically less costly.

[0007]

【Example】

 A diff lock device when an embodiment of the present invention is applied to a lawnmower will be described below with reference to the drawings. A front mower type riding lawn mower is shown in FIG. 3, where 1 is a front drive wheel, 2 is a mission case, 3 is an engine, 4 is a control section, 5 is a steering rear wheel, M is a mower, and 6 is an aircraft frame. is there. The transmission case 2 is internally provided with a diff device 7 and a diff lock device A, and the structure thereof will be described below. As shown in FIGS. 1 and 2, the left and right output diff shafts 8 of the diff device 7 correspond to the front axle, and the claws 9 formed at the side ends of the diff case 20 are slidable in the axial direction. Further, a diff lock device A is constituted by a diff lock mechanism 11 which is formed by engaging and disengaging an annular claw clutch member 10 which is splined on the front axle 8 and an operating mechanism 12 for opening and closing the diff lock mechanism 11. The operation mechanism 12 is arranged so as to straddle the operation shaft 15 in which a pin insertion hole is formed, the operating body 17 on the cylinder shaft in which the inclined groove 14 is formed, the hole of the operation shaft 15 and the inclined groove 14. It comprises an engaging pin 16 and a shift fork 18 which is inserted and fixed in the operating body 17, and a lever 19 attached to the tip of the operating shaft 15 and a diff lock operating lever 13 provided in the control section 4 are interlocked with the wire. The cantilevered shift fork 18 having the root fixed to the operating body 17 has a root portion 18a passing through the operation long hole 21 formed in the mission case 2 and a larger diameter than the root portion 18a, and The pressing surface 18c is formed by cutting, and the tip portion 18b is engaged with the peripheral groove 10a formed in the outer peripheral portion of the claw clutch member 10 at only one location. The shift fork 18 is created by cutting out from a single round bar, and the pressing surface 18c is set on the diff lock-in operation side by sliding the claw clutch member 10 to the claw portion 9. The claw clutch member 10 is brought into the face-to-face contact state. If the shift fork 18 and the operating body 17 are relatively rotatably fitted to each other, it is convenient in that the pressing surface 18c and the circumferential groove 10a are brought into contact with each other.

It should be noted that reference numerals are added to the claims of the utility model for convenience of comparison with the drawings, but the invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a diff lock device.

FIG. 2 is an exploded perspective view showing a structure near a shift fork.

[Fig. 3] Side view of a riding lawn mower

FIG. 4 is a sectional view showing a conventional structure of a diff lock device.

[Explanation of symbols]

 8 Output Diff Shaft 9 Claw 10 Claw Clutch Member 10a Circumferential Groove 11 Diff Lock Mechanism 12 Operation Mechanism 18 Shift Fork 18b Tip 18c Pressing Surface 20 Differential Case

Claims (1)

[Scope of utility model registration request] 1. A claw portion (9) formed at a side end of a differential case (20) and an annular claw clutch member (10) spline-fitted onto an output differential shaft (8) so as to be slidable in an axial direction. ) Diff lock mechanism (11)
And a shift fork (18) for slidingly operating the claw clutch member (10) in the operation mechanism (12). The tip portion (18b) is constituted by a single cantilevered round bar that engages with the peripheral groove (10a) formed in the outer peripheral portion of the claw clutch member (10) only at one location, and the tip portion is formed. (18
A diff lock device in which a pressing surface (18c) is formed on the tip portion (18b) by cutting so that the b) and the side wall surface of the claw portion of the circumferential groove (10a) come into contact with each other.