JPH0115953Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an automatic transmission that automatically switches the transmission gears of an automobile. This invention relates to a shock mitigation device.

(Prior art) Generally, automatic transmissions are equipped with a manual valve that switches the hydraulic oil path in response to manual operation by a passenger, and when this manual valve is switched from the N range to the D range, the pressure Hydraulic fluid with line pressure from the regulator valve is supplied to the forward clutch. At this time, if the line pressure is supplied too rapidly to the friction element of the forward clutch, a so-called select shock occurs, resulting in poor riding comfort.

To prevent such selection shots,
Conventionally, an orifice b as shown in Fig. 1 was provided in the middle of an oil passage a connecting a manual valve and a forward clutch (Nissan Full Automatic).
3N71B type maintenance manual (revised edition) 1976 edition 36-37
Figure 54 (Hydraulic circuit diagram inserted between pages, published by Nissan Motor Co., Ltd.) temporarily lowers the hydraulic fluid supplied to the forward clutch below the line pressure to gradually increase the forward clutch engagement hydraulic pressure. In this way, the shock is reduced by extending the engagement time of the forward clutch. The line pressure increases when the idling rotational torque of the engine at the time of starting is large, that is, when the idling rotational speed of the engine becomes high. The engine's idling speed increases when the engine temperature is low, and returns to the normal idling speed when the engine temperature rises, due to an automatic engine yoke that operates in response to engine temperature. The select shock becomes particularly large when the line pressure is high, that is, when the idling speed of the engine is high, which poses a problem in riding comfort.

However, the orifice in the oil passage used in the shock reduction device of such conventional automatic transmissions cannot change the opening area of the oil passage, so once it is fixed, the opening area cannot be adjusted. The rise characteristics of the clutch engagement hydraulic pressure remained approximately constant regardless of the magnitude of the line pressure. Therefore, in order to effectively prevent a large selection shock when the line pressure is high, that is, when the engine idling speed is high, reducing the oil passage opening area of the orifice will reduce the engine idling speed. When the forward clutch returns to normal, the forward clutch engagement time becomes too long. Conversely, when the line pressure is low, that is, when the engine idling speed is normal, the forward clutch engagement time is shortened, and the oil passage opening area of the orifice is increased. When the idling speed is high, the select shock becomes large. Therefore, the opening area of the oil passage of the orifice has to be compromised, and both of the above two problems cannot be reliably solved.

(Purpose of the invention) Therefore, the present invention provides a variable orifice means in the middle of the oil passage that connects the manual valve of the automatic transmission and the forward clutch. It is an object of the present invention to solve the above-mentioned problems by minimizing the oil passage opening area of the variable orifice means.

(Structure of the invention) An automatic transmission mounted on a vehicle equipped with an autochoke mechanism that increases the idling speed of the engine when the temperature of engine cooling water is in a predetermined low temperature range, the manual valve of the automatic transmission In the middle of the oil path connecting the forward clutch and the forward clutch,
A variable orifice means is provided that reduces the opening area of the oil passage when receiving a predetermined operating force, and while the autochoke mechanism is increasing the idling speed of the engine, the variable orifice means generates a predetermined operating force. It is configured by providing an operating means for providing the information.

(Operation and effect of the invention) According to this configuration, that is, technical means,
When the autochoke mechanism operates and the idling speed increases, that is, when the hydraulic oil line pressure increases, the oil passage opening area of the orifice can be minimized to effectively prevent the large select shock. Also, when the autochoke mechanism is released and the idling speed returns to normal, that is, when the hydraulic oil line pressure decreases, the oil passage opening area of the orifice is expanded to shorten the engagement time of the forward clutch. be able to.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 2 is a diagram showing an embodiment of the present invention.

First, to explain the configuration, in Figure 2, 1
is an oil passage that connects the manual valve of the automatic transmission (not shown) and the forward clutch of the automatic transmission. There is a variable orifice hole 1 in the middle of the oil path 1.
a is formed, and this variable orifice hole 1
One end of the orifice former 2 is fitted into the hole a so as to be slidable in a direction perpendicular to the axis of the oil passage 1. A flange portion 2 a is formed at the other end of the orifice former 2 , and the flange portion 2 a engages with one end portion of an orifice holding bracket 3 fixed to the oil passage 1 . An oil seal 4 is interposed between the orifice former 2 and one end of the orifice holding bracket 3 to prevent oil in the oil passage 1 from leaking outside. The other end of the orifice holding bracket 3 and the flange portion 2 of the orifice former 2
A coil spring 5 is interposed between the coil spring 5 and the oil passage 1, and always urges the orifice former 2 toward the oil passage 1 side. One end of a connecting wire 7 is fixed to the other end of the orifice former 2, and when the connecting wire 7 is pulled toward the side opposite to the oil passage 1, the orifice former 2 is moved by the biasing force of the coil spring 5. It is movable so as to expand the oil passage opening area. Orifice former 2, orifice holding bracket 3, oil seal 4, coil spring 5
The connecting wire 7 constitutes a variable orifice means 50 as a whole. The outside of the orifice holding bracket 3 of the connecting wire 7 is covered with a tube 8, and one end of the tube 8 is held by a first wire support bracket 9 fixed to the orifice holding bracket 3. The other end of the connecting wire 7 is fixed to one end of a connecting rod 10, which will be described later. A second wire support bracket 11 that holds the other end of the tube 8 covering the connecting wire 7 is fixed to the vehicle body (not shown) near the connecting rod 10. The connecting wire 7 and tube 8 are slidable relative to each other. Connecting rod 1
A pin 14 supported by a pin holding bracket 13 fixed to the vehicle body (not shown) is inserted in the middle of the 0, and the connecting rod 10 can be rotated around this pin 14. The other end of the connecting rod 10 is connected to one end of a wax plunger 15, which is an automatic yoke mechanism (not shown) and will be described later. The wax plunger 15 is designed to generate a displacement (hereinafter, this displacement will be referred to as an engine temperature signal) in response to the temperature of the engine cooling water. The wax plunger 15 operates to increase the idling speed of the engine when the engine temperature signal corresponds to a predetermined low temperature range, and is released to increase the idling speed of the engine when the engine temperature signal corresponds to a predetermined low temperature range. It is an autochoke mechanism that returns the number to normal. The wax plunger 15 not only outputs an engine temperature signal to a carburetor (not shown) as a function of the automatic yoke mechanism, but also inputs an output signal in the form of displacement to the other end of the connecting rod 10 as described above. There is. Connecting rod 10, pin retaining bracket 13, pin 14 and wax plunger 15 together constitute operating means 60 of the variable orifice means.

Next, the action will be explained. wax plunger 15
detects the temperature of the engine cooling water, and when the temperature is high, the wax plunger 15 is displaced to the right in the figure due to melting and expansion of wax (not shown). Due to this displacement of the wax plunger 15, one end of the connecting rod 10 rotates to the left in the figure, using the pin 14 as a fulcrum, and pulls the other end of the connecting wire 7 to the left in the figure. The connecting wire 7 slides within the tube 8 and its one end is pulled upward in the figure, resisting the biasing force of the coil spring 5 and pulling the orifice former 2 upward in the figure. Therefore, the oil passage opening area formed by the orifice former 2 is expanded, and the pressure drop of the hydraulic oil is reduced. At this time, the engine's idling speed is normal and the line pressure is low due to the automatic engine yoke mechanism. Therefore, it is possible to prevent the engagement time of the forward clutch from increasing when the idling speed of the engine is normal.

Furthermore, when the wax plunger 15 detects the temperature of the engine cooling water and the engine temperature signal is below a predetermined value, the wax plunger 15
is displaced to the limit point on the left side of the figure. Due to this displacement of the wax plunger 15, one end of the connecting rod 10 rotates to the right in the figure using the pin 14 as a fulcrum, and pushes the other end of the connecting wire 7 to the right in the figure. The connecting wire 7 slides within the tube 8, and one end of the connecting wire 7 is pushed down in the figure, and together with the biasing force of the coil spring 5, the orifice former 2 is pushed down in the figure. Therefore, the oil passage opening area formed by the orifice former 2 is narrowed to a minimum, and the pressure drop of the hydraulic oil increases. At this time, the engine's idling speed is high and the line pressure is high due to the automatic engine yoke mechanism. Therefore, it is possible to effectively prevent a large selection shock that tends to occur when the idling speed of the engine is high.

Furthermore, depending on the shape of one end of the orifice former 2 and the spring constant of the coil spring 5, the variable orifice means can also function as an accumulator, and the select shock can be adjusted even further when the engine is idling. can be reduced over the entire rotation range.

In this embodiment, physical and mechanical means were used as the operating means for the engine temperature detection means and variable orifice means, but these means may also be constituted by electrical sensors, circuits, solenoids, etc. Needless to say, it's a good thing.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional side view of an orifice in an oil passage that is a conventional shock reduction device for an automatic transmission, and Fig. 2 is a partially sectional side view showing an embodiment of the shock reduction device for an automatic transmission according to the present invention. It is a diagram. 1... Oil path, 2... Orifice former, 3...
Orifice holding bracket, 4... Oil seal, 5... Coil spring, 7... Connecting wire, 10... Connecting rod, 13... Pin holding bracket, 14... Pin, 15... Wax plunger, 50... Orifice variable means, 60... operating means.

Claims (1)

[Scope of Claim for Utility Model Registration] An automatic transmission installed in a vehicle equipped with an autochoke mechanism that increases the idling speed of the engine when the temperature of engine cooling water is in a predetermined low temperature range, the automatic transmission as described above. A variable orifice means is provided in the middle of the oil passage connecting the manual valve and the forward clutch to reduce the opening area of the oil passage when a predetermined operating force is applied, and the autochoke mechanism increases the idling speed of the engine. What is claimed is: 1. A shock reduction device for an automatic transmission, characterized in that an operating means is provided which generates a predetermined operating force and applies it to the variable orifice means while the variable orifice is being operated.