JPH0652093B2 - Forward / reverse switching device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward / reverse switching device for use in a vehicle such as a tractor, and provides a down / forward switching device having a small number of parts.

2. Description of the Related Art A conventional forward / reverse switching device is provided with a forward counter gear and a reverse counter gear on a counter shaft that has a counter gear that meshes with an input gear of an input shaft that is axially supported by a transmission case, and is arranged in parallel with the counter shaft. A forward gear and a reverse gear are loosely fitted to the output shaft that is supported by the shaft, and a reverse idle gear that meshes with both the reverse gear and the reverse counter gear is loosely attached to the reverse shaft that is fixed to the mesh case. It is configured such that the forward gear or the reverse gear can be selectively coupled to the output shaft by the engagement switching mechanism, and thus, the input shaft, the output shaft, and the counter shaft arranged in parallel with these, Further, since the reverse shafts are mounted in parallel, there is a disadvantage that the forward-reverse switching device becomes large especially in the cross-sectional shape and the mesh mechanism becomes large. In addition, since the shift mechanism is required to be capable of multi-speed shifting, it is required that the deceleration switching device be arranged at an appropriate position in relation to other shift mechanisms in the shift mechanism according to the specifications. For this purpose, the device must be small enough and
It is necessary to be able to construct without the need for parallel pivots for many axes.

Problems to be Solved by the Invention The present invention has been devised so as to downsize the forward / reverse switching device and eliminate the need for parallel arrangement of related shafts.

Means for Solving Problems The present invention has taken the following technical means in order to solve the above problems.

That is, the input shaft and the output shaft provided concentrically with the input shaft, the carrier loosely fitted to the output shaft, the carrier provided on the carrier concentrically with the carrier, and axially supported in the front and rear positions respectively. A gear, an input gear provided on the input shaft so as to mesh with the preceding gear, and an output gear provided on the output shaft so as to mesh with the latter gear via an idle gear pivotally supported by the carrier. And a multi-plate friction clutch part for switching between forward and backward movements, which allows the carrier to be selectively coupled to a boss part provided on the output shaft or to a mission case, and a friction plate brake part, and The forward / reverse switching device is characterized in that the forward side of the multi-plate friction clutch portion is always urged by an elastic body to be in the clutch-engaged state, and the backward side is composed of a hydraulic clutch and controlled by a solenoid valve. .

Embodiment and Action Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 4 shows a gear mechanism of the traction mechanism of the tractor to which the embodiment is applied. The rotation of the engine (1) is transmitted to the clutch output shaft (3) by the main clutch (2). A main transmission mechanism (5) that includes a main transmission counter gear group (5) that interlocks the rotation of the clutch output shaft (3) with the gear (4) of the clutch output shaft (3) and a main transmission gear group (6) that meshes with the main transmission mechanism (6). The speed of the input shaft (8) is transmitted to the input shaft (8) by the gear shifter (7), and the power of the input shaft (8) is moved forward or backward to the output shaft (10) by the forward-reverse switching device (9) described below. Each of them is switched and transmitted, and the rotation of the output shaft (10) is transmitted to the output shaft (1
(0) gear (11) in conjunction with a sub-transmission counter gear group (12) and a sub-transmission gear group (13) that meshes with the sub-transmission mechanism (14) to change the speed and drive pinion shaft ( The drive pinion shaft (15) drives the rear wheels (17) and (17) via the rear wheel differential mechanism (16).

The forward / reverse switching device (9) includes a tubular frame (1) loosely fitted to the output shaft (10).
The carrier (19) is fixed to the carrier (8) with bolts (20), (20), and a plurality of gear pins (21) and gear pins (21) are attached to the carrier (19) on a concentric circle centered on the output shaft (10). 22) are provided and fixed, the input gear (23) is provided at the rear of the input shaft (8), and the output gear (24) is provided at the front of the output shaft (10), which are formed as one body with each other. The front gear (26) and the rear gear (27) are rotatably attached to the respective gear pins (21) via the bearings (25) (25), and the front gear (26) is input. Mesh with the gear (23) and engage each gear pin (2
2) The idle gear (29) rotatably provided to the output gear (27) and the rear gear (27) through the bearings (28) and (28) engages the tubular frame (18). At the front, attach the boss (3) to the output shaft (10).
(0) is fixed, and behind the tubular frame (18) is the case (3
Attach the bearing body (32) to the 1) with bolts (33), (33) ... so that the tubular frame (18) can be connected to the boss (30) or unconnected. The spring-operated multi-plate friction clutch section (C) and the hydraulically-operated friction plate brake section that can switch the tubular frame (18) to the bearing body (32) or to the uncoupled state ( B) are provided respectively. That is, the illustrated multi-plate friction clutch portion (C) has a ring-shaped pressing plate (34), (3) in the tooth-shaped groove formed on the outer peripheral portion of the boss portion (30).
4) Engages the tooth-shaped grooves formed in the inner holes of the ring-shaped separator plates (35), (35) with the tooth-shaped grooves formed on the outer peripheral portion of the front part of the tubular frame (18). The separator plate (35) is interposed between the presser plates (34) and (34) by engaging the tooth-like grooves of the separator plate (35) with the partition wall (18a) of the tubular frame (18) and the separator plate (3).
The plate (36) located at the rearmost part of (5) is inserted in the direction of arrow A in FIG. 1 by the spring (37) interposed between the plate and the plate (36).
(36), separator plate (35), press plate (3
4) are attached to each other so that the tubular frame (18) is
The friction plate brake unit, which will be described next,
In the state where pressure oil is supplied to the cylinder chamber (38) of (B), the clutch piston (39) causes the plates (40) and (36) and the connecting pin (41) connecting them to move in the direction of arrow in FIG. Since it moves in the direction of the line A, the elasticity of the spring (37) is canceled and the separator plate (35) and the pressure plate (34) are separated from each other so that the cylindrical frame (1
8) is configured to be in a non-bonded state with the boss portion (30).

The friction plate brake section (B) engages the tooth groove of the bearing plate (42) with the tooth groove of the boss portion of the bearing body (32),
A cylinder chamber formed in the front part of the tubular frame (18) by engaging the toothed groove of the separator plate (43) with the toothed groove of the tubular frame (18).
When the clutch piston (39) fitted to (38) is hydraulically moved in the direction of the arrow A, the plate plate (42) and the separator plate (43) are in contact with each other and thereby the cylinder Frame
(18) will be in a state of coupling with the bearing body (32), and the cylinder chamber (3
8) When the pressure oil inside has been discharged to the outside,
Due to the restoring force of the spring (37) of (B) in the direction of arrow A, the plates (40) and (36) and the connecting pin (41) connecting them move the clutch piston (39) in the direction of arrow A. To move to
The pressure plate (42) and the separator plate (43) are separated from each other so that the tubular frame (18) is not coupled to the bearing body (32).

Therefore, when the tubular frame (18) is connected to the boss (30), the carrier (19), the output gear (24), and the output shaft (10) are all in one body, so the input shaft (8), The output shaft (10) is directly connected to the input shaft (8) by connecting the input gear (23), gears (26), (27), output gear (24) and output shaft (10) to one, (10) will rotate in the direction of advancing the vehicle, and when the tubular frame (18) is disengaged from the boss (30), the tubular frame (18) becomes the bearing body (32). Since they are connected, the carrier (19) stands still, and the rotation of the input shaft (8) causes the meshing of the input gear (23) and the gear (26) and the gear (27), the idle gear (29) and the output gear ( 24) Input shaft
The output shaft (10) is rotated in the reverse direction, which is the opposite direction to (8).

In order to supply pressure oil to the cylinder chamber (38), the electromagnetic solenoid (44a) of the clutch switching valve (44) is energized based on the switching operation of the switching switch (45), and the pressure oil of the oil pump (46) is discharged. Oil pipe (47), bearing body (32) oil passage (32a), output shaft (10) oil passage (10
a), it is formed to communicate with the cylinder chamber (38) via the oil passage (18b) of the tubular frame (18).

The gear pins (21), (22) are provided with notches for preventing rotation at their rear end portions, and the separator plate (35) engaging the tooth groove of the cylindrical frame (18) with the tooth groove. The gear pin is formed so that the inner hole of the foremost (leftmost in FIG. 1) of
(21) and (22) are cylindrical frame (18) and this and one carrier (19)
It is designed to reduce costs by eliminating the need for separate rotation stoppers.

In FIG. 4, reference numeral (48) is a PTO clutch, and PT
The PTO shaft (50) is driven by the O transmission mechanism (49).

EFFECTS OF THE INVENTION Since the present invention is as described in detail in the above-mentioned one embodiment, when the pressure oil is not supplied to the cylinder chamber (38),
Since the multi-plate friction clutch portion (C) is configured to be coupled by the elastic force of the spring (37), the multi-disc friction clutch portion (C) is used as an assist for starting the engine and assisting the parking brake when the battery power is consumed. Engine braking during natural rolling is possible, and traveling is possible even when a failure occurs in the hydraulic system. Moreover, during forward traveling, the multi-plate friction clutch section (C) is engaged by the spring (37) and pressure is applied. Since oil is unnecessary, the engine output has the advantage that it can be used without waste during traveling during work traveling. Further, in the forward / reverse switching device according to the present invention, the input shaft (8) and the output shaft (10) are concentric with each other, and the gears (26) (2) related to the forward / reverse switching are provided.
7) and the idle gear (29) are rotatably supported by a carrier (19) concentric with the input shaft (8) and the output shaft (10), so that the input shaft (8) and the output shaft which are in the front-rear same shaft center. (1
It is possible to switch between forward and reverse between 0) and 0). Thus, the forward / reverse switching device can be downsized particularly in its cross-sectional shape, and many shafts like the above-mentioned conventional device can be used. Since the shafts must be supported in parallel with each other, the disadvantages that tend to become large can be solved by the present invention.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a vertical cross-sectional side view of a main part of a mesh mechanism, FIG. 2 is a vertical cross-sectional view showing a shaft support state of an idle gear, and FIG. 3 is D- of FIG. FIG. 4 is a gear diagram of the mission mechanism, as seen from the direction of the arrow D. Symbol Description (8) …… Input shaft, (10) …… Output shaft (19) …… Carrier, (23) …… Input gear (24) …… Output gear, (26) (27) …… Gear (29 ) …… Idle gear, (30) …… Boss part (31) …… Mission case, (B) …… Friction plate brake part (C) …… Multi-plate friction clutch part

Claims (1)

[Claims] 1. An input shaft, an output shaft provided concentrically with the input shaft, a carrier loosely fitted to the output shaft, a carrier arranged concentrically with the carrier, and axially supported integrally with each other. Each gear, the input gear provided on the input shaft so as to mesh with the preceding gear, and the output shaft so as to mesh with the latter gear via an idle gear pivotally supported by the carrier. An output gear, a boss provided on the output shaft of the carrier, or a multi-plate friction clutch part for switching between forward and reverse, which can be selectively coupled to a mission case, and a friction plate brake part. In addition, the forward side of the multi-plate friction clutch portion is urged by an elastic body to be always in the clutch-engaged state, and the reverse side is composed of a hydraulic clutch and is controlled by a solenoid valve. apparatus.