JPH032052Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is capable of switching between two-wheel drive and four-wheel drive and
The present invention relates to a shift device for a four-wheel drive transfer that switches between high speed, neutral, and low speed after switching to wheel drive.

(Prior Art) Conventionally, as a shift device for an auxiliary transmission of a four-wheel drive vehicle, the one shown in FIG. 2, for example, is known (Japanese Patent Laid-Open No. 55-91419, etc.).

Figure 2 schematically shows a shift device with a 2H-4H-4N-4L linear shift pattern together with a shift mechanism built into the transfer section. 8 and 4H-4 in four-wheel drive mode
A fork rod 10 equipped with a shift fork 9 for switching between N-4L is provided so as to be freely slidable in the axial direction. The movement of the shift lever 1 is transmitted to the link lever 14 via the link rod 3, and the rotation of the link lever 14 sequentially moves the fork rods 8 and 10 in the axial direction via the link arm 16. That is,
In the illustrated state where the two-wheel drive 2H is selected, the stopper pin 15 fits and locks the fork rod 10 on the four-wheel side, and when the shift position is changed to 4H in this state, the link lever 14 rotates clockwise. The fork rod 8 and the shift fork 9 are simultaneously pushed to the right by the link arm 16 shown in broken lines.
However, because the stopper pin 15 is inserted, the fork rod 10 and shift fork 9 cannot move, and only the fork rod 8 moves to the right, and the shift fork 7 activates a synchronizing mechanism (not shown) to switch to four-wheel drive. . At this time, the stopper groove 17a of the fork rod 8 moves to a position where the stopper pin 15 is retracted.

Next, shift from shift position 4H to neutral position 4N.
When switching to the stopper pin, the link lever 14 further rotates clockwise, and since the link arm 16 on the fork rod 8 side is fixed, the rotation of the link lever 14 moves the fork rod 10 through the link arm 16 to the stopper pin. 15 into the stopper groove 17a and move it to the right side, and then press the ball groove 1
Ball 19 pressed by spring against 8b
Move the shift fork 9 to the neutral position 4N determined by the fit. Furthermore, neutral position 4N
to shift position 4L, stopper pin 1
The same operation is performed by rotating the link lever 14 in a state in which the locking by the link lever 5 is released.

(Problems to be Solved by the Invention) However, such conventional shift devices without a neutral stopper have the following problems.

First, when switching from 2H to 4H while driving, a large operating force is required for synchronization, but as soon as the synchronization is completed, the operating force is no longer needed, so 4H is skipped and 4H is switched.
There is a risk of falling into N. In this case, once the vehicle enters 4N, stop the vehicle and then
Therefore, the function of being able to switch from 2H to 4H while driving cannot be effectively utilized.

Second, if you accidentally shift from 4L to 4N while driving on a steep slope, etc., you may lose control of the vehicle.

Therefore, for the inventor of the present application, for example, the third
The jump to 4N when shifting from 2H to 4H or from 4L to 4, as schematically shown in the figure.
In order to prevent an erroneous shift to N, we have proposed a device using a mechanical stopper that requires pushing the shift lever 1 before and after the neutral position 4N.

That is, the rod portion of the shift lever 1 is provided with a connecting structure that allows it to move forward and backward in the axial direction, and the shift lever 1 is connected before and after the neutral position 4N.
A shift plate 2 can be provided to stop the movement of the shift plate 2 and provide a shift pattern for pushing operation.

However, even with a shift device using such a mechanical stopper, the following problems occur.

First, referring to the characteristic diagram shown in Fig. 4, which shows the relationship between the shift load and the shift position, due to the accumulation of tolerances of mechanical parts, there is a variation in the distance l between the synchronization start point and the stopper position between 2H and 4H. Due to this variation, the load applied by the stopper pin to the stopper during synchronization may become as small as P1. Therefore, there was a risk that the shifter would hit the stopper before applying sufficient operating force necessary for synchronized operation, resulting in a shift error.

In order to solve this problem, it is necessary to improve the precision of mechanical parts, which results in an increase in costs.

In addition, since there are many parts from the shift lever to the shift fork, the rigidity of the control system is low.If the rigidity was high, the load P3 when the stopper pin hits the stopper during synchronization could be obtained, but because the rigidity is low, , the load becomes small as P2.

In order to avoid this, it is necessary to increase the rigidity of the mechanical parts, but this increases the size and weight of the parts, which is also effective in terms of cost.

Furthermore, the mechanical system has the problem that the stopper mechanism becomes large and the degree of freedom in vehicle design is restricted.

(Problems to be solved by the invention) The present invention was made in view of the above problems, and achieves prevention of jump operation to the neutral position when using a linear shift pattern with a simple mechanical structure. An object of the present invention is to provide a shift device for a four-wheel drive transfer. In order to achieve this objective, the present invention sequentially switches between 2-wheel drive 2H, 4-wheel high-speed 4H, 4-wheel neutral 4N, and 4-wheel low-speed 4L according to the shift operation of the shift lever according to a linear shift pattern. In a shift device for a four-wheel drive transfer, a stopper pin is provided for locking a fork rod for selecting high speed, neutral, and low speed in four-wheel drive operated in conjunction with a shift lever before and after the neutral position, and The stopper pin is provided with an actuator that moves the stopper pin in and out, and when a stopper release switch provided on the shift lever is operated, the actuator is operated to retract the stopper pin and release the fork lock.

(Example) FIG. 1 is a cross-sectional explanatory diagram showing an example of the present invention. Note that the shift lever portion is schematically shown on a reduced scale.

First, the construction will be explained. Reference numeral 1 denotes a shift lever, and the movement of the shift lever 1 is transmitted to a link lever 14 provided at the transfer of the sub-transmission via a link rod 3 shown by a two-dot chain line.

As a shift mechanism built into the transfer,
8 is a fork rod for switching between two-wheel drive and four-wheel drive, that is, 2H and 4H, to which a shift fork 7 for switching between 2H and 4H is fixed. 10
is a fork rod that switches between 4H-4N-4L (high-speed 4-wheel drive position - neutral position - low-speed 4-wheel drive position) in the 4-wheel drive switching state, and has a shift fork 9 fixed thereto. The movement of the shift lever 1 is transmitted to a link lever 14 that rotates around a shaft 14a, and an arm link 16 shown by a broken line is rotatably attached to the tip of the link lever 14, and both ends of the arm link are connected to each other. Folklod 8,1
It is engaged on the 0 side.

There is no stopper mechanism on the fork rod 8 side that switches between 2-wheel drive and 4-wheel drive, and the left side of the fork rod 10 that switches between 3 positions in 4-wheel drive mode has shift positions 4H, 4N, and 4.
Three ball grooves 18 defining each shift position of L
a, 18b, 18c are provided, and this ball groove 1
The fork rod 10 is positioned by fitting balls 19 pressed by springs into the balls 8a to 18c. In addition, Four Clod 1
Two stopper grooves 22a and 22c are formed on the right side of the shifter 0 in correspondence with shift positions 4H and 4L, and a stopper pin 21 that engages with the stopper grooves 22a and 22c is provided, and the stopper pin 21 can freely protrude and retract from the actuator 20. It is set in. As the actuator 20, an appropriate actuator may be used, such as one that causes the stopper pin 21 to move in and out by turning on and off an electromagnetic solenoid, or one that operates a diaphragm to move the stopper pin 21 in and out by controlling a vacuum by turning on and off a solenoid valve. used.

On the other hand, in order to operate the stopper pin 21 by the actuator 20, a stopper release switch 24 is incorporated into the knob 23 provided at the tip of the shift lever 1. As the stopper release switch 24, a push button switch or a so-called touch switch that detects a touch on the knob 23 and closes a switch contact is used. Stopper release switch 4
A battery voltage +Vb is applied to one of the contact terminals, and the other contact terminal is connected to the actuator 20 by a signal line 25, and the actuator 20 is turned on by turning on the stopper release switch 4.
The stopper pin 21 is pulled in by supplying an operating voltage to the stopper pin 21.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

First, when operating the shift lever 1 from 2H to 4H, the stopper release switch 24 provided on the knob 23 is not turned on.

This movement of the shift lever 1 from 2H to 4H causes the link lever 14 to rotate clockwise, and since the stopper pin 21 is fitted into the stopper groove 22a at this time, the fork rod 10 does not move.
When the link lever 14 rotates, the arm link 16 uses the upper side as a fixed fulcrum and the lower side rotates to the right, moving the fork rod 8 to the right and shifting the shift fork 7.
A shift operation from two-wheel drive 2H to four-wheel high speed 4H is performed.

Next, from shift position 4H to neutral position 4
When shifting to N, the shift lever 1 is shifted to the neutral position 4N while turning on the stopper release switch 24 provided on the knob 23.
By turning on the stopper release switch 24 at this time, power is supplied to the actuator 20, and the stopper pin 21 is retracted by the operation of the actuator 20, and the stopper pin 21 is moved into the stopper groove 22a.
The fork rod 10 is released from the lock. By shifting the shift lever 1 to the neutral position 4N, the link lever 14 further rotates clockwise.At this time, since the movement of the fork rod 8 to the right is stopped by switching to 4H, the arm link 16 is moved downward. The upper side rotates to the right with the side as a fixed fulcrum, and the fork rod 10 moves to the right while pushing down the stopper pin 15 into the opposing pin groove 17a, and the shift fork 9 operates the transfer shaft to the neutral position 4N. By this movement of the fork cloth 10 to the neutral position 4N, the ball 19 is moved to the ball groove 1.
8b, and the stopper pin 21 of the actuator 20 is opposed between the stopper grooves 22a and 22c, and when the shift to the neutral position 4N is completed, the power supply to the actuator 20 is cut off by turning off the stopper release switch 24. Also, the stopper pin 21 is placed in the retracted state.

Furthermore, from neutral position 4N to shift position 4
When switching to L, press the stopper release switch 24.
You can shift as is without turning on, and at shift position 4L, the stopper pin 21 is in the stopper groove 22.
Get stuck in c. .

On the other hand, from shift position 4L to neutral position 4
When shifting to N, the actuator 20 is actuated by similarly turning on the stopper release switch 24, and the stopper is released by retracting the stopper pin 21 before shifting.

In the above embodiment, when shifting from 4H or 4L to the neutral position after switching to four-wheel drive, it is necessary to turn on the stopper release switch 24 provided on the shift knob. Due to the synchro operation, even if you apply a large operating force when shifting to 4H, it will not jump over 4H and shift to neutral 4N, and of course, even if you shift to 4L on a slope, etc.
It can also be reliably prevented from entering the neutral position 4N by mistake.

In addition, since the stopper is released electrically by operating the stopper release switch, the mechanism structure is simpler than that of a mechanical stopper, and there is no influence from tolerances or rigidity of the control system from the shift lever to the fork rod. The degree of freedom in design can also be increased.

(Effects of the invention) As explained above, according to the invention, stopper pins are provided on the four-wheel side fork rods for locking the fork rods at high speed and low speed positions before and after the neutral position, and this stopper pin is Since the stopper release switch provided on the shift knob is operated to activate the actuator, the mechanical part consisting of the stopper pin and actuator is placed inside the transfer shaft, and the stopper mechanism is provided in the control system from the shift lever to the fork rod. It is possible to reliably prevent erroneous operation to the neutral position even in a linear shift pattern without being affected by the tolerance or rigidity of the mechanical parts constituting the control system.

Furthermore, since the control system does not have a stopper mechanism, the shift load is not restricted and a sufficiently large shift load for synchronized operation can be obtained.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram showing a conventional example, Fig. 3 is an explanatory diagram showing an example of a mechanical stopper, and Fig. 4 is an explanatory diagram showing an example of a mechanical stopper. FIG. 3 is a characteristic diagram showing the relationship between shift position and shift load in FIG. 1: Shift lever, 2: Shift plate, 3:
Link rod, 8, 10: Four rod, 7,
9: Shift fork, 14: Link lever, 1
6: Arm link, 18a-18c: Ball groove,
19: Ball, 20: Actuator, 21: Stopper pin, 22a, 22c: Stopper groove, 2
3: Knob, 24: Stopper release switch, 25:
Signal line.

Claims (1)

[Scope of claim for utility model registration] Two-wheel drive 2 depending on the shift operation of the shift lever
H, 4-wheel high-speed 4H, 4-wheel neutral 4N, and 4-wheel low-speed 4L in a shift device for a 4-wheel drive transfer that sequentially switches between 4-wheel high speed 4H, 4-wheel neutral 4N, and 4-wheel low speed 4L, in which the high speed in the 4-wheel drive state is operated in conjunction with the shift lever; A stopper pin that locks a fork rod for neutral and low speed selection before and after the neutral position, an actuator for retracting and retracting the stopper pin, and a stopper pin provided on the shift lever and actuated by a release operation to retract the stopper pin and lock the fork rod. A shift device for a four-wheel drive transfer, comprising a stopper release switch for releasing the lock.