JPH0219345B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a negative pressure/force conversion device for an automatic transmission, and particularly to an automatic transmission that can electrically detect that negative pressure has exceeded a predetermined value. This relates to a negative pressure/force conversion device for aircraft.

(B) Prior Art Some automatic transmission control devices for vehicles need to detect that the engine is in an idling state (that is, a fully closed throttle state). For example, when using a torque converter with a lock-up mechanism, some models release the lock-up mechanism when the throttle is fully closed; It is also necessary to detect whether the throttle is fully closed when performing control such as downshifting. In addition, there are cases where it is necessary to detect the fully closed state of the throttle to control the combustion state of the engine. For this purpose, a mechanical switch has conventionally been provided at a linkage or other connection between the accelerator pedal and the engine throttle. Examples include an idle switch that is turned on when no pedal force is applied to the accelerator pedal, and an idle switch provided on a throttle sensor for electrically detecting the throttle opening degree.

(c) Problems to be Solved by the Invention However, in the case of an idle switch installed on the accelerator pedal, there is a problem in that the on/off state of the switch may not completely correspond to the idling state. In other words, if you place your foot on the accelerator pedal and apply almost no pedal force, the switch may remain off even though the engine is idling.
The switch may also be turned on and off by slight vibrations acting on the foot. Furthermore, if an idle switch is provided on the accelerator pedal, a special accelerator pedal must be provided for this purpose, which is expensive and unfavorable from the viewpoint of manufacturing control.
On the other hand, in the case of a type in which the throttle opening sensor is provided with an idle switch, there is a problem that it can only be applied to an automatic transmission having a throttle opening sensor. In the case of an automatic transmission that does not have a throttle opening sensor, it is necessary to add a special switch to the linkage, etc. The present invention aims to solve the above-mentioned problems and to make it possible to reliably detect the idling state without adding a separate switch.

For example, Japanese Utility Model Publication No. 55-40352 discloses an acceleration detection switch that detects a rapid increase in the amount of depression of the accelerator pedal, which is equipped with a switch operated by a diaphragm. . However, this is only for detecting an acceleration state, not for converting negative pressure into force, nor is it for detecting an idling state of the engine. Moreover, the structure is also complicated.

(d) Means for Solving the Problems The present invention achieves the above object by providing a switch contact in a vacuum diaphragm, which is a negative pressure/force converting device for an automatic transmission. That is, the negative pressure/force conversion device for an automatic transmission according to the present invention has switch contacts 40 on the negative pressure chamber 16 side portion of the diaphragm 14 and the stationary portion 20 on the negative pressure chamber side, respectively.
a and 40b are provided, and both switch contacts are turned on by the displacement of the diaphragm when the negative pressure acting on the negative pressure chamber exceeds a predetermined value corresponding to the idling state of the engine, and are turned off in other cases. It is set to be. Note that the reference numerals in parentheses indicate corresponding members in the embodiments described later.

(e) Operation With the above configuration, when the negative pressure reaches a value corresponding to the idling state of the engine, the diaphragm is displaced and the switch contact is turned on. Therefore, the signal at the switch contact corresponds reliably to the idling state of the engine.

(F) Embodiments Hereinafter, embodiments of the present invention will be described based on FIGS. 1 and 2 of the accompanying drawings.

First Embodiment FIG. 1 shows a negative pressure/force converter for an automatic transmission which is a first embodiment of the present invention. Negative pressure for automatic transmission
Vacuum diaphragm 10 which is a force conversion device
is provided in combination with the throttle valve 12. A vacuum diaphragm 10 attached to the valve body 13 has a negative pressure chamber 16 and an atmospheric pressure chamber 18 partitioned by a diaphragm 14 . The negative pressure of the engine intake pipe acts on the negative pressure chamber 16 through the inlet pipe 20, while the atmospheric pressure chamber 18
Atmospheric pressure acts on A spring 24 is provided within the negative pressure chamber 16 so as to apply a force to the left in FIG. 1 on the diaphragm 14. One switch contact 40a is provided at the center of the plate 22 attached to the diaphragm 14 so as to serve as a seat for the spring 24.
The other switch contact 40b is provided at the tip of the inlet pipe 20 so as to face this switch contact 40a. Switch contact 40b and inlet pipe 20
An electrical insulating material 42 is interposed between the two. A covered wire 44 is connected to the switch contact 40b, and this covered wire 44 is taken out to the outside of the negative pressure chamber 16. The surface of the diaphragm 14 on the atmospheric pressure chamber 18 side is connected to the throttle valve 12 via a rod 26.
The spool 28 is connected to the spool 28. That is, the diaphragm 14 is connected to the spool 2 via the rod 26.
A pushing force can be applied to 8. The throttle valve 12 provided within the valve body 13 is
The line pressure supplied from the oil passage 30 is used as the oil pressure source, and the oil pressure (throttle pressure) of the oil passage 32 is applied to the rod 2.
The pressure is adjusted to correspond to the pushing force from 6.

Next, the operation of this embodiment will be explained. The negative pressure of the engine intake pipe acts on the negative pressure chamber 16, while the atmospheric pressure acts on the atmospheric pressure chamber 18, so the diaphragm 14 moves to the first position in proportion to the negative pressure.
It receives a force in the right direction in the figure. On the other hand, spring 2
4 exerts a force to the left in FIG. 1 on the diaphragm 14. Therefore, a force obtained by subtracting the force due to the negative pressure from the force of the spring 24 acts on the rod 26. That is, rod 2
6 is acted upon by a force that decreases as the negative pressure increases. Since the throttle valve 12 regulates the throttle pressure in the oil passage 32 according to the force from the rod 26, the throttle pressure has a pressure characteristic that decreases as the negative pressure increases. When the negative pressure becomes very large, the force acting on the diaphragm 14 is increased by the spring 2.
When the force is greater than the force due to 4, diaphragm 1
4 starts to be displaced to the right in FIG. When the negative pressure increases to a predetermined value, the switch contacts 40a and 40b come into contact with each other due to the displacement of the diaphragm 14. If the value of the negative pressure at this time is made to match the value of the negative pressure when the engine is idling, the switch contacts 40a and 40b will be turned on in the idling state, and the signal of the covered wire 44 will be used to control the lock-up mechanism, etc. It can be used as an idling signal.
Note that the switch contact 40a is grounded via a plate 22 and a spring 24. Since the switch contacts 40a and 40b are turned on and off in response to the actual negative pressure in the engine intake pipe, the idling state of the engine can be detected more reliably than when a mechanical switch is provided in the throttle linkage, for example. can do. In addition, the switch contacts 40a and 40b are connected to the vacuum diaphragm 1.
Since it is located inside the idle switch, no extra space is required for the idle switch. In addition, there are 40 switch contacts on the normal vacuum diaphragm.
Since the idle switch can be constructed by simply providing the wires a, 40b and the covered wire 44, the price can be reduced.

Second Embodiment FIG. 2 shows a second embodiment of the present invention. This second
In this embodiment, a female thread is provided on the inner diameter of the inlet pipe 20, a hollow adjustment member 46 having a thread is screwed into this, and a switch contact 40 is provided at the tip of this adjustment member 46.
b. The rest of the structure is the same as the first embodiment shown in FIG. In this second embodiment, the position of the switch contact 40b can be adjusted by adjusting the screwing amount of the adjusting member 46. As a result, even if the negative pressure during idling differs depending on the type of engine, adjustment can be made so that the switch contacts 40a and 40b are turned on in a desired state.

(g) Effects of the Invention As explained above, according to the present invention, a switch contact is provided between the diaphragm and the stationary part on the negative pressure chamber side, and this switch contact is connected to the engine when the negative pressure is in the idling state. Since the diaphragm is turned on by displacement of the diaphragm when the value exceeds a predetermined value corresponding to , it is possible to reliably detect the idling state of the engine. In addition, the structure for this purpose is simply such that the switch contacts come into contact with each other when the diaphragm is displaced by a predetermined amount toward the negative pressure chamber, resulting in a simple structure and a very low price.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a negative pressure/force converter for an automatic transmission which is a first embodiment of the present invention, and FIG. 2 is a diagram showing a negative pressure/force converter for an automatic transmission which is a second embodiment of the present invention. FIG. 10... Vacuum diaphragm (negative pressure/force conversion device for automatic transmission), 12... Throttle valve, 14... Diaphragm, 16... Negative pressure chamber, 1
8... Atmospheric pressure chamber, 40a, 40b... Switch contacts, 44... Covered wire.

Claims (1)

[Scope of Claims] 1. Negative pressure for an automatic transmission for converting negative pressure into force by applying negative pressure of an engine intake pipe to a diaphragm, and applying this force to a throttle valve to adjust oil pressure.・It is a force conversion device, and the diaphragm is arranged to separate an atmospheric pressure chamber open to atmospheric pressure and a negative pressure chamber connected to the engine intake pipe, and the diaphragm receives atmospheric pressure from the negative pressure chamber side. A spring that applies a force toward the chamber is provided, and the atmospheric pressure chamber side of the diaphragm is connected to the spool of the throttle valve so as to exert a pushing force thereon. A switch contact is provided on each stationary part on the room side.
Both switch contacts are turned on by the displacement of the diaphragm when the negative pressure acting on the negative pressure chamber exceeds a predetermined value corresponding to the idling state of the engine.
A negative pressure/force conversion device for an automatic transmission, characterized in that it is set to be turned off in other cases.