JPH0454364Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention is based on a shift fork shaft that is arranged parallel to a main shaft that supports the change gears of a transmission, in which a plurality of shift forks can be freely slid in accordance with the gear position. The present invention relates to a shift position or select position detection device in a transmission equipped with a select actuator for selectively engaging each shift fork with a shift fork shaft.

[Prior Art] This type of transmission has a mechanism as shown in Utility Application No. 1983-79338, which was previously proposed by the applicant, and uses an air actuator to operate a multi-gear transmission. This is a highly practical device that can automatically operate the shift fork.

In such a transmission, it is necessary to detect and provide feedback on the position of the shift fork shaft that drives the shift fork and the position of the select actuator that engages and disengages the shift fork.

Conventionally, mechanical switches have been used as sensors for detecting this position, which has caused reliability problems due to deterioration due to wear and chattering phenomena.

Therefore, a device using a magnetic switch for this position detection is shown as Utility Model Application No. 116659/1983,
Since it was simply a magnet attached to the shaft, the position detection accuracy was not necessarily high.

Further, Japanese Utility Model Application Publication No. 59-35804 discloses a technique in which a recess is provided in the shift rod and a magnetic sensor is provided on the gear box side in order to detect the position of the shift rod. However, in both this known technology and the above-mentioned known technology, the neutral position is not detected during select and shift operations, so the neutral state cannot be detected, and as a result, the automatic gear shift operation is not performed accurately, resulting in gear noise, etc. It has the following disadvantages.

[Problem to be Solved] Therefore, the purpose of the present invention is to detect the gear position of an automatic transmission, which can accurately detect the gear position, smoothly perform the automatic gear shifting operation of the automatic transmission, and eliminate inconveniences such as gear noise. We are in the process of providing equipment.

[Means for Solving the Problems] According to the present invention, a plurality of shift forks corresponding to the gears are slidably attached to a single shift fork shaft arranged parallel to the main shaft that supports the change gears of the transmission. In addition, in an automatic transmission equipped with a select actuator that selectively engages each shift fork with the one shift fork shaft, the shafts of both the shift fork shaft and the select piston shaft of the select actuator have irregularities. In the vicinity of the concave and convex portion provided on this one shift fork shaft, there is a shift position having magnetic detection terminals at three positions corresponding to the neutral position, one shift position, and the opposite shift position. Only one detection sensor is arranged, and an on signal is generated in each select piston shaft of the plurality of select actuators when the shift fork and the shift fork shaft are integrated, and they are not integrated. A select position detection sensor that sometimes generates an off signal is provided for each select piston shaft.

[Description of operation and effect] Therefore, the shift signal moves the shift fork shaft to one of the shift positions, and causes the select actuator of the selected shift fork shaft to operate. Then, a predetermined transmission engages the gear.
At this time, in automatic transmissions, the clutch is operated by an actuator, but by detecting the neutral position, it is possible to automatically perform the so-called double clutch operation that is carried out in ordinary transmissions. As a result, synchronization work can be carried out suitably and gear noise can be prevented.

The uneven portion formed on the shift forkshaft consists of a recess provided at the neutral position of the shift forkshaft, and depending on the position of this recess, the shift forkshaft can determine whether the neutral position is one shift position or the opposite shift position. This can be determined by the detection sensor. The concavo-convex portion of the select piston shaft is constituted by a convex ring portion formed on the top of the piston, and is similarly detected by a select position detection sensor.

Such an arrangement not only improves the durability and reliability, which are characteristics of the magnetic sensor, but also improves environmental resistance against adhesion of grease, oil, etc. and vibration. Furthermore, since the magnetic sensor is small, narrow transmissions can be made more compact, giving more freedom in design.

In addition, in the present invention, by forming uneven portions on the shaft, detection accuracy can be increased and automatic gear shifting operations can be performed correctly.

In this way, the present invention can prevent double meshing of gears when a single shift fork shaft operates multiple shift forks to perform automatic gear shifting.
Furthermore, since the position of the shift forkshaft including the neutral position can be detected, the clutch can be suitably controlled during automatic gear shifting.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an outline of a transmission embodying the present invention, in which an input side 2 of a transmission main body 1 is connected to an engine side, and an output side 3 is connected to a drive shaft side.

On the main shaft in the transmission are gears 4a for 5-4 speeds and gears 4 for 3rd-2nd speeds from the engine side 2.
b. 1st-reverse gears 4C are arranged, and sliding sleeves 5a, 5b, 5c for engaging and disengaging each gear are connected to each gear unit 4a, 4b,
It is provided in the center of 4c. This sliding sleeve 5 slides on the main shaft by a shift fork 6, which is engaged with a shift fork shaft 7 arranged parallel to the main shaft. This shift fork shaft 7 is supported by a cover 8 attached to the upper part of the transmission body 1.

One end of the shift fork shaft 7 is connected to a piston shaft 11 of a shift actuator 10. This piston shaft 11 is integrally attached to the piston 13.
slides within the cylinder 12 of the actuator together with a pair of collars 14A, 14B slidably fitted to the outer periphery thereof. Inside this cylinder 12 are 2
Two chambers A and B are formed, and by alternately supplying air or the like to these chambers A and B, the piston 13 is driven and the shift fork 7 is caused to slide.

When equal pressure is supplied to chambers A and B, color 1
4A and 14B, the piston 13 is returned to the neutral position, and the shift fork shaft 7 is also held at the neutral position.

The operation of the shift fork shaft 7 is selectively transmitted to the shift fork 6 via the select actuator 20 to operate each shift fork, but the details of the select actuator 20 are as follows.
As shown in the figure.

The select actuator 20 has a cylinder 21 formed on the upper part of the transmission cover 8, and a select piston 22 is slidably inserted into the cylinder 21. The lower end of the select piston is in contact with a first select pin 23, and a second select pin 24 is inserted into the shift fork shaft 7 below the first select pin 23. A return spring 25 is placed within the shift fork 6 and constantly urges the select pin 24 upward via a push rod 26.

On the other hand, a set spring 28 is attached to the upper part of the select piston 22, and the piston 28 after actuation is
biases downward. For example, there is an air supply hole 29 in the upper part of the cylinder 21.
Press down the select piston by supplying air from As a result, the first select pin 23 is pushed into the shift fork 6 and pin-engages the shift fork 7 and the shift fork 6. Therefore, the transmission operating section 35 shown in FIG.
When the shift lever of the transmission is operated according to the shift pattern, the select actuator 20 corresponding to the shift position is driven, and only the selected shift fork 6 engages with the shift fork shaft 7 to perform the corresponding shift. mesh the gears.

A recess into which an interlock pin 30 is inserted is formed on both sides of the center of the select piston 22, and an interlock ball 31 is in contact with this recess. Therefore, when the select piston 22 descends, the interlock ball 31 is pushed out of the recess, causing the interlock shaft to slide. This movement is transmitted to the adjacent select actuator, and the interlock ball restricts the movement of the select piston.

Therefore, while a certain shift fork is engaged with the shift fork shaft, other shift forks cannot be engaged, and double meshing of the gears is prevented.

The shift position of the shift fork is detected by a shift position detection sensor 40 placed around the shift fork shaft, and the position of the select piston 22 is detected by a select position detection sensor 50 provided at the top of the select actuator 20. be done.

FIG. 2a shows details of the shift position detection sensor 40. The sensor body is attached to the transmission cover 8, and a magnetic sensor circuit 41 is provided inside. Magnetic detection terminals 42a, 42b, and 42c are connected to this magnetic sensor circuit 41, and when the concave portion 7a of the shift fork shaft 7 approaches each terminal, this is magnetically detected and sent to the circuit 41. , whose output signals are on lines 43a, 4
3b and 43c, the signal is fed back to the transmission operating section 35.

Similarly, the main body of the select position detection sensor 50 is attached to the top of the select actuator 20 and has an internal circuit 51. Internal circuit 5
1 are connected to magnetic detection terminals 52a and 52b, and when the convex ring portion 22a formed at the top of the select piston 22 approaches, it is magnetically detected and a vibration is transmitted from the circuit 51 to the line 53.
a, 53b to the transmission operating section 35.

[Effects of the invention] As described above, the invention provides the following excellent effects.

(1) In an automatic transmission that uses one shift fork shaft and multiple shift forks, while one shift fork is engaged with the shift fork shaft, other shift forks cannot be engaged, resulting in double meshing. can be prevented.

(2) Detection of three positions ensures accurate automatic clutch operation, allowing automatic gear shifting without gear noise.

(3) The features of the magnetic sensor can be fully utilized, and reliability can be improved without reducing reliability due to wear or malfunction due to adhesion of grease, oil, etc.

(4) The position of each shaft can be detected with a simple structure of forming uneven parts.

[Brief explanation of drawings]

FIG. 1 is a side view showing a transmission body implementing the present invention, FIG. 2 is a detailed view of a shift actuator and a position detection sensor, and FIG. 2a is a detailed view of a shift position sensor. 1...Transmission body, 6...Shift fork, 7
...Shift fork shaft, 7a...Recess, 8
... Cover, 10 ... Shift actuator, 2
0...Select actuator, 22...Select piston, 22a...Convex ring, 23, 24...
...Select pin, 35...Transmission operation section, 40...
...Shift position detection sensor, 41...Internal circuit, 4
2a, 42b, 42c...terminal, 50...select position detection sensor, 51...internal circuit, 52a,
52b...Terminal.

Claims (1)

[Scope of utility model registration request] A plurality of shift forks corresponding to the gears are slidably attached to a single shift fork shaft arranged parallel to the main shaft that supports the change gears of the transmission, and each shift fork is selectively attached to the single shift fork shaft. In an automatic transmission equipped with a select actuator that engages with a shift fork shaft, uneven portions are formed on both shafts of the shift fork shaft and the select piston shaft of the select actuator, and this single shift fork shaft is In the vicinity of the provided uneven portion, only one shift position detection sensor having magnetic detection terminals is arranged at three positions corresponding to the neutral position, one shift position, and the opposite shift position,
Each select piston shaft of the plurality of select actuators has a select position that generates an on signal when the shift fork and the shift fork shaft are integrated, and generates an off signal when they are not integrated. A gear position detection device for an automatic transmission, characterized in that a detection sensor is provided for each select piston shaft.