JPH0348440Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an improvement of a transmission gear shift device.

(Prior art) In recent years, in order to reduce driver fatigue, more and more vehicles are equipped with automatic transmissions that automatically shift gears by interposing a torque converter between the engine and the transmission. ing.

Of these, in order to improve not only ease of operation but also fuel efficiency, conventional transmissions and mechanical clutches are used, and instead of the driver operating the clutch and transmission, these are controlled electronically. The present applicant has proposed an automatic transmission device that automatically performs a speed change operation.

Incidentally, in such an automatic transmission, a transmission gear shift device as shown in FIGS. 2 and 3 is employed (see Utility Model Application No. 105237/1983).

A fork shaft 11 is attached to the transmission cover 18 in parallel with a main shaft (not shown) so as to be able to freely slide in the axial direction. Shift forks 12 for 3rd speed and 2nd speed and 1st speed and reverse are respectively disposed to be freely slidable in the axial direction.

The shift actuator 13 (air cylinder) moves the forkshaft 11 in the axial direction, that is, shifts the fork shaft 11. When air pressure is supplied to either one of the air pressure chambers A and B and the other air pressure is released, , the piston 14 slides in the direction of reducing the air pressure chamber A or B on the low pressure side, and the piston rod 15
Shift the forkshaft 11 connected to. 16A and 16B are the piston 14, that is, the forkshaft 1 when the air pressure chambers A and B are at the same pressure.
1 to the neutral position.

On the other hand, one selection actuator 19 (air cylinder) is disposed on the transmission cover 18 at a neutral position corresponding to each of the shift forks 12.

Each of the selection actuators 19 switches between atmospheric pressure and air pressure in its air pressure chamber 19B.
A push rod 19A moves forward and backward through a guide hole 21C, which will be described later. 27 indicates a return spring of the push rod 19A.

Guide holes 21A to 21C are formed in the fork shaft 11, shift fork 12, and transmission cover 18 at neutral positions and coaxially and straightly communicate with the push rod 19A of the select actuator 19. 21C, the shift fork 12 is connected to the transmission cover 18 and the shift shaft 1 as the actuator 19 expands and contracts as described later.
1 as an engager to be restrained to either one of the
and second lock pins 22 and 23 are slidably interposed.

24 is a spring that biases the second and first locking pins 22 and 23 toward the transmission cover 18; 25 is a locking ball for positioning; this locking ball shallowly enters the guide hole 21A at the neutral position; It is adapted to fit into a recess 26 of the forkshaft 11.

Therefore, at the time of gear shifting, at the neutral position (the plurality of select actuators 19 are in the contracted state),
When one of the select actuators 19 is extended, its push rod 19A pushes in the first and second lock pins 22 and 23, releasing the shift fork 12 from the cover 18 and restraining it to the fork shaft 11. At this time, the other shift fork 12 is restrained to the transmission cover 18 by the first lock pin 22.

Next, when air pressure is supplied to either one of the air pressure chambers A and B of the shift actuator 13,
The fork shaft 11 performs a shift operation, but at this time the shift fork 1 restrained by the shaft 11
Only the gears 2 move together to engage the gears.

To return the transmission 10 to neutral, open both air pressure chambers A of the shift actuator 13.
When the air pressures of and B are the same, the fork shaft 11 returns to the neutral position together with the piston 14, and the gears are disengaged via the shift fork 12.

Next, the select actuator 19 in the extended state may be retracted. In this case, the first and second lock pins 22 and 23 are pushed by the spring 24, and the first lock pin 22 moves the shift fork 12 into the transmission. It is restrained by the cover 18.

According to this, even when the number of gears of the transmission 10 increases, selection operation can be performed using the two-position actuator 19 with a simple configuration, gear shift control becomes easy, and the fork shaft 11 only has one gear. Not only that, but
Link mechanisms such as select levers and shift levers can also be eliminated, making the device more compact and lightweight.

(Problem to be solved by the invention) However, in such a gear shift mechanism, since the select actuator is an air cylinder, it takes time to transmit air pressure, etc.
There was a problem that a responsive selection operation could not be obtained.

(Means for Solving the Problem) Therefore, this invention is a gear shift device for a transmission in which a plurality of shift forks are slidably provided on a fork shaft.
Each select electromagnetic actuator is provided, and each shift fork is provided with an engager that restrains the shift fork to either the shift shaft or the transmission cover as the select electromagnetic actuator expands and contracts in a neutral position; An interlock mechanism is provided to prevent a selection electromagnetic actuator from simultaneously restraining a plurality of shift forks to a fork shaft.

(Function) That is, since an electromagnetic actuator is employed as the select actuator, the select operation can be performed reliably with good responsiveness.

(Example) In Fig. 1, 11 is a forkshaft, 12
1 is a shift fork, 18 is a transmission cover, and the transmission cover 18 is provided with a selection electromagnetic actuator 30 corresponding to each shift fork 12.

When the electromagnetic coil 31 is energized, the electromagnetic actuator 30 compresses the spring 32 and draws the iron core 33 inside the electromagnetic coil 31 .

Fork shaft 11, shift fork 12,
The transmission cover 18 is in the neutral position,
Guide holes 21A to 21C are formed coaxially and in straight communication with the iron core 33 of the electromagnetic actuator 30, and the shift fork 12 is inserted into the guide holes 21A to 21C as the actuator 30 is driven.
A plunger 34 as an engager that selectively restrains the transmission cover 18 and the shift shaft 11, and the first and second lock pins 35 and 3.
6 is slidably inserted. Reference numeral 37 indicates a spring that biases the second lock pin 36 toward the transmission cover 18.

During gear shifting, one of the electromagnetic actuators 30 is in a neutral position (all electromagnetic actuators 30 are de-energized and the shift fork 12 is restrained to the transmission cover 18 side by the plunger 34 as shown). When energized, as the iron core 33 is retracted inside the electromagnetic coil 31, the second and first lock pins 36 and 35 and the plunger 34 are pushed up by the urging force of the spring 37, and the shift fork 12 is pushed up. the first and second
It is restrained to the forkshaft 11 side by lock pins 35 and 36.

Next, a shift actuator (not shown)
When a shift operation is performed, only the shift fork 12, which is restrained by the fork shaft 11, moves together to engage the gears.

In addition, in order to return the transmission to neutral, it is sufficient to return the shift actuator to the neutral position, and when the shift fork 12 restrained by the fork shaft 11 releases its gear engagement and returns to the neutral position, the plunger 34 is moved again. is restrained to the transmission cover 18 side by.

Reference numeral 40 indicates that when one of the electromagnetic actuators 30 is energized, that is, when the shift fork 12 is restrained to the shift shaft 11 by the first and second lock pins 35 and 36, the other electromagnetic actuator 30 is The movement of the plunger 34 is fixed even when energized. That is, this is an interlock mechanism that prevents two or more shift forks 12 from being restrained by the shift shaft 11 at the same time. As the plunger 34 moves upward, the check ball 43 is pushed out from the approximately hemispherical fitting recess 42.
The check ball 43 of the adjacent plunger 34 is pushed into the fitting recess 42 via the rod 44 and locked. Reference numeral 45 designates a pin that slides on the plunger 34 and pushes out the other check ball 43 as one check ball 43 is pushed into the fitting recess 42 in order to similarly lock the adjacent plunger 34.

(Effects of the invention) In summary, according to this invention, since an electromagnetic actuator is used as the select actuator, it does not take time to transmit air pressure, which is the case with air cylinders, which causes delays in operation. The effect is that the selection operation can be performed reliably with good responsiveness.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts showing an embodiment of this invention.
FIG. 2 is a partially cutaway side view showing the prior art, and FIG. 3 is a sectional view of the main part thereof. 11...Fork shaft, 12...Shift fork, 18...Transmission cover, 2
1A to 21C... Guide hole, 30... Electromagnetic actuator for selection, 34... Plunger, 3
5, 36...Lock pin, 40...Interlock mechanism.

Claims (1)

[Scope of utility model registration request] In a transmission gear shift device in which a plurality of shift forks are freely slidable on a forkshaft, an electromagnetic actuator for selection is provided on the transmission cover for each shift fork, and a select electromagnetic actuator is provided for each shift fork. An engager is provided that restrains the shift fork to either the shift shaft or the transmission cover as the select electromagnetic actuator expands and contracts in the neutral position, while the select electromagnetic actuator simultaneously restrains multiple shift forks to the fork shaft. A gear shift device for a transmission characterized by being provided with an interlock mechanism that prevents the transmission from occurring.