JPS61103016A - Automatic speed change gear - Google Patents

Abstract

PURPOSE:To reduce a change in engagement shock due to a temperature change by providing a throttle device of an automatic speed change gear circuit constructed so that a throttle opening area is varied according to the temperature of working fluid. CONSTITUTION:A throttle 4 comprises a throttle valve 5 and a valve working fluid path 8 passing a choke 6 and an orifice 7 to be drained, wherein pre- passing oil pressure PL in the valve working fluid path 8 is applied to the valve end surface 5a on the open area enlarge side of the throttle valve 5, and inter- throttle oil pressure PA in the valve working fluid path 8 is applied to the valve end surface 5b on the open area reduce side of the throttle valve 5. In this arrangement, even if the viscosity of working fluid varies with fluid temperature, and the viscosity is high or low, the open area is controlled to keep constant the flow rate passing through the throttle under any temperature condition and to eliminate a change in engagement time and shock due to a temperature change.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic transmission, and particularly to a throttle device provided in an operating pressure circuit that guides engagement pressure to engagement elements such as clutches and brakes.

(Prior Art) As a conventional throttle device for an automatic transmission, for example, a device as shown in Fig. 6 is known ("Near Sun Automatic Transmission 9i Instructions L4N71B Type, E4N71B Type", November 1982). (Published by Nissan Motor Co., Ltd.; see page 34).

This conventional device uses a clutch 100 as a fastening element.
A fixed orifice 102 was provided as a restrictor in the line pressure oil passage lO1 that supplies fastening pressure to the cylinder.

In addition, what is indicated by 103 in the figure is a manual valve, 10
4 is a pressure regulator valve, and 105 is an oil pump.

Therefore, in conventional equipment, N range (neutral range)
When shifting from to D range (automatic shift range), the spool 106 of the manual valve 103 moves to the D range position, and the hydraulic oil, which is at line pressure by the pressure regulator valve 104, is transferred to the manual valve 103.
and the rear clutch 100 after passing through the line pressure oil passage lot.
guided by.

However, this line pressure oil passage 101 has a fixed orifice 1.
By providing 02, the hydraulic oil is gradually introduced to the rear clutch 100, and the engagement shock that would occur when line pressure hydraulic oil is introduced all at once can be alleviated.

(Problem to be Solved by the Invention) However, in such a conventional device, the opening area is a fixed orifice 102 that is fixed, and the opening area is set such that it can exert a fastening shock mitigation effect at a predetermined constant temperature. Therefore, at low temperatures, the flow rate at the fixed orifice 10.2 decreased due to the high viscosity of the hydraulic oil, causing the disc of the rear clutch 100 to slip and requiring a long time to engage. There is a problem in that the flow rate at the fixed orifice 102 increases due to the low viscosity of the hydraulic oil, resulting in a shortening of the fastening time and a fastening shock.

(□,.□O6i#(7)l□JR) The present invention is
This invention was made with the purpose of solving the above-mentioned problems, and to achieve this purpose, the present invention employs the following solving means.

This solving means will be explained with reference to the diagram corresponding to the claims shown in FIG.
In an automatic transmission having a throttle 4 in
Consisting of a throttle valve 5 whose opening area S changes by sliding, and a valve operating oil passage 8 drained through a plurality of throttles (chokes 6 and orifices 7), the opening area of the throttle valve 5 is expanded. The pre-elapsed oil pressure PL of the valve operating oil passage 8 was applied to the side valve end face 5a, and the inter-restriction oil pressure FA of the valve operating oil passage 8 was applied to the reduced opening area side valve end face 5b of the throttle valve 5.

(Function) Therefore, in the automatic transmission of the present invention, by using the above-mentioned means, since the viscosity of the oil flowing through the valve operating oil passage 8 is high at low temperatures, the pre-current oil pressure PL
is high, the inter-throttle oil pressure FA becomes low, and the differential pressure causes the throttle valve 5 to slide in the direction in which the opening area S increases.

As a result, the highly viscous hydraulic oil passing through the hydraulic pressure circuit 3 is guided to the fastening element 1 through the aperture 4 having a wide opening area S, and the flow rate at the aperture 4 does not become insufficient.

Furthermore, at high temperatures, the viscosity of the oil flowing through the valve operating oil passage 8 is low, so the pressure difference between the pre-lapse pressure PL and the throttle pressure FA decreases, and the opening area S of the throttle valve 5 decreases. .

As a result, the low-viscosity hydraulic oil passing through the hydraulic pressure circuit 3 is guided to the fastening element 1 through the throttle 4 having a narrow opening area S, and the flow rate at the throttle 4 does not increase.

In this way, even if the viscosity of the hydraulic oil differs depending on the oil temperature, when the viscosity is high, the opening area S expands, and when the viscosity is low, the opening area S decreases, so that the oil passes through the throttle 4 under any temperature condition. It is possible to keep the flow rate almost constant and reduce changes in fastening time and fastening shock due to changes in temperature.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In describing this implementation, a rear clutch throttling device used in an automatic transmission with three forward speeds and one reverse speed will be taken as an example.

First, FIG. 2 schematically shows the power transmission part inside the automatic transmission, including the crankshaft 21. Torque converter 22. Input shaft 23. Front clutch 24. Hendo Serpo 25. mission case 2
6. Rear clutch 27. Connecting shell 28. Front planetary gear 29. Rear planetary gear 30° Roam reverse brake 31. One way clutch 32
．． Output shaft 33. Parking pole 34.
It is composed of an oil distributor 35.

In the figure, 36 is an oil pump, 37 is a secondary governor valve, and 38 is a briny governor valve.

Further, the rear clutch 27 is connected to the input shaft 2
It includes a driven plate 40 provided on the clutch drum 39 on the third side, a drive plate 43 provided on the clutch hub 42 on the internal gear 41 side, and a clutch piston 44 for engaging the clutch.

Next, FIG. 3 shows a hydraulic control circuit used in the above-mentioned automatic transmission, in which the above-mentioned oil pump 36, secondary governor valve 37, . The primary governor valve 38 is provided as a hydraulic control means provided in the control valve section.
Vacuum diaphragm45. A downshift solenoid 46 is provided, and the control valves provided in the control valve section include a pressure regulator valve 47, a manual valve 48.1-2 shift valve 49.2-3 shift valve 50. Pressure modifier valve 51
．． Vacuum throttle j! , valve 52.
Throttle backup valve 53, solenoid town shift valve 54. Second lock valve 55.2-3
The above-mentioned torque converter 22. is equipped with a timing valve 56 and serves as a hydraulic output side means provided in the power transmission section.
Front clutch 24. Rear clutch 27. Band servo 25. Equipped with low & reverse brake 31.

Note that these means and valves are connected by oil passages.

The fastening elements at each shift position of the automatic transmission according to the embodiment operate as shown in Table 1 below.

Table 1 By the way, Figure 3 shows the hydraulic control circuit for the first speed of the D range. Among the oil passages in this circuit, the oil passages to which hydraulic pressure such as line pressure is guided are the parts indicated by side diagonal lines. A line pressure oil passage 57, a gas pressure oil passage 58 indicated by large diagonal lines, and a throttle pressure oil passage 59 indicated by thin cross diagonal lines,
This is the portion of the torque converter/heater pressure oil passage 60 shown with scattered dots.

Among the fastening elements, front clutch 24, rear clutch 27. The low & reverse brake 31 and the band servo 25 are provided with the throttling device of the embodiment in the line pressure oil passage immediately before them, and here the throttling device 61 of the rear clutch 27 is shown in FIG. explain.

61 is a throttle device, and this throttle device 61 includes a valve body 62 and a sleeve 63 inserted into the valve body 62. It is composed of a throttle valve 64 and a spring 65.

62 is a valve body, and this valve body 62 has line pressure ports 66, 67 and an input line pressure port 6.
8, an output line pressure port 69, and an orifice 70 are formed.

The line pressure ports 66 and 67 and the input line pressure port 68 are connected from the oil pump 36 to the pressure regulator valve 47. A branch oil passage 57a is connected to the line pressure oil passage 57 through which the line pressure is introduced after passing through the manual valve 48.
, 5'7b, and 57c, and the output line pressure boat 69 is connected to an engagement line pressure oil passage 57d that communicates with the hydraulic oil chamber 71 of the rear clutch 27.

Note that the oil passing through the orifice 70 is drained.

Reference numeral 63 denotes a sleeve, which is fixed inside the valve body 62, and this sleeve 63 is provided with a choke 72 formed by an elongated hole.

One end surface 63a of the sleeve 63 is disposed in a first line pressure chamber 73 that communicates with the line pressure port 66, and the other end surface 63b is disposed in an inter-restriction oil chamber 74 that communicates with the orifice 70.

Reference numeral 64 denotes a throttle valve, which is slidably inserted into the eight valve body 62. A conical surface portion 64a is formed on the circumferential surface of the throttle valve 64, and as the throttle valve 64 slides, , the opening area S formed between this conical surface portion 64a and the inner surface 62a of the valve body 62 changes.

One end surface 64b of the throttle valve 64 is disposed in the inter-throttle oil chamber 74, and a spring 65 is interposed between the one end surface 64b and the other end surface 63b of the sleeve 63. It is biased to the right (in the direction in which the opening area S is reduced). Further, the other end surface 64c of the throttle valve 64 is arranged in a second line pressure chamber 75 that communicates with the line pressure port 67.

Next, the operation of the embodiment will be explained.

First, when a shift is performed from the N range to the D range by a shift operation, the spool 76 of the manual valve 48 moves to the D range position, and as shown in the line pressure oil passage 57 in FIG. The line pressure that has passed through the pressure regulator valve 47 is guided to the line pressure oil path 57 to the rear clutch 27 through the line pressure ports 77 and 78 of the manual valve 48, and then passes through the throttle device 61 of the embodiment. The clutch piston 44 is guided to the engagement line pressure oil passage 57d that communicates with the hydraulic oil chamber 71 of the rear clutch 27.
is operated to engage the rear clutch 27, which is a forward gear clutch.

Here, the variable throttling action of the throttling device 61 will be described at low temperatures and at high temperatures.

(a) At low temperatures (see Figure 4) At low temperatures, the oil used in automatic transmissions has a high viscosity, so the line pressure oil passage 57 → line pressure boat 66 → first line pressure chamber 73 is guided. When the oil at the reduced line pressure passes through the choke 72, its flow rate is significantly reduced due to viscous resistance, and the inter-restriction pressure FA in the inter-restriction oil chamber 74 between the choke 72 and the orifice 70 becomes low.

On the other hand, the line pressure oil guided from line pressure oil passage 57 to line pressure port 67 to second line pressure chamber 75 is not throttled, so in second line pressure chamber 75 high line pressure PL It is.

Therefore, the throttle pressure PA b< acts on one end face 64b of the throttle valve 64, and the line pressure PL acts on the other end face 64c. is line pressure PL
Slide it to the position where it is balanced (to the left in the drawing).

By this sliding of the throttle valve 64, the opening area S is expanded, and the line pressure oil that has passed through the line pressure oil passage 57 → branch oil passage 57c → line press-fit capotro 8 is not subjected to a high throttle action. It is guided to the operating line pressure oil passage 57d, and the rear clutch 27 is engaged.

(b) At high temperatures (see Figure 5) At high temperatures, the viscosity of oil is low, so the viscous resistance when passing through the choke 72 is also small, and the inter-restriction pressure FA in the inter-restriction oil chamber 74 is at the line Pressure PL
The pressure is close to .

Therefore, the pressure difference between the end faces 64b and 64c of the throttle valve 64 is almost eliminated, the throttle valve 64 does not slide, or only slightly slides, and the opening area S becomes narrow.

For this reason, the line pressure oil that causes the rear clutch 27 to be engaged is subjected to a high throttling action and its flow rate is restricted, preventing the rear clutch 27 from being suddenly engaged.

In this way, even if the viscosity of the oil varies depending on the oil temperature, the opening surface MS serving as the throttle portion can be set to the opening area S that can keep the flow rate substantially constant according to the viscosity.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. included.

For example, in the embodiment, the throttle device of the rear clutch of an automatic transmission has been described, but the throttle device of the present invention may be applied to other engagement elements such as clutches and brakes.

In addition, in the embodiment, a hydraulic oil passage that operates the fastening element;
Although the valve operating oil passage for operating the throttle valve is formed by the same line pressure oil passage, it is also possible to use separate oil passage systems.

Further, in order to obtain the inter-restriction oil pressure, a choke and an orifice are used in the embodiment, but the present invention is not limited to the embodiment as long as the inter-restriction oil pressure is obtained using a plurality of orifices.

(Effects of the Invention) As explained above, according to the automatic transmission of the present invention, the throttle device is configured so that the throttle opening area in the working pressure circuit is variable depending on the temperature of the working oil. The effect of reducing the change in the fastening time of the fastening element and the change in the fastening shock caused by the fastening element can be obtained.

[Brief explanation of drawings]

Fig. 1 is a complaint correspondence diagram showing the automatic transmission of the present invention, Fig. 2 is a schematic diagram showing the power transmission part of the automatic transmission of the embodiment, and Fig. 3 is a hydraulic pressure diagram at the first speed of the drive range of the automatic transmission. A circuit diagram showing the control circuit, Fig. 4 is a sectional view showing the throttle device of the embodiment at low temperature, Fig. 5 is a sectional view showing the throttle device of the embodiment at high temperature, and Fig. 6 is a conventional automatic transmission. FIG. 1... Fastening element 2... Control valve 3... Working pressure circuit 4... Throttle 5... Throttle valve 6... Choke (throttle) 7... Orifice (throttle) 8... Valve hydraulic oil passage 5a... Valve end face on the enlarged opening area side 5b... Valve end face on the reduced opening area side PL... Hydraulic pressure before passage FA... Hydraulic pressure between the throttles Patent application Hito-Nissan Motor Co., Ltd.

Claims (1)

[Claims] 1) In an automatic transmission having a throttle in the operating pressure circuit between a fastening element and a control valve, the throttle is replaced by a throttle valve whose opening area changes by sliding, and a valve which drains through a plurality of throttles. A hydraulic oil passage is configured to apply pre-pressure hydraulic pressure of the valve hydraulic oil passage to the valve end face on the enlarged opening area side of the throttle valve, and a hydraulic oil pressure of the valve hydraulic oil passage is applied to the valve end face on the narrowing opening area side of the throttle valve. An automatic transmission characterized by applying hydraulic pressure between the throttles.