JPS647255B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to automatic transmissions for vehicles, and in particular to the use of torque converters by making slight improvements to conventional mechanical transmissions of the constant mesh type. This invention relates to a simple automatic transmission having a structure that allows smooth automatic gear shifting.

Traditionally, large vehicles such as trucks and buses have used manual transmissions, but with these, the change lever is difficult to operate and the upper gears often have a large stroke, making driving operations easier. However, the disadvantage was that the driver was easily fatigued. In order to overcome this drawback, it is possible to adopt an automatic transmission using a torque converter, but this would only increase fuel consumption due to the large power loss caused by fluid slippage. However, those for large vehicles have drawbacks such as being extremely expensive, making it difficult to adopt them. Therefore, it is possible to adopt a mechanical automatic transmission that does not use a torque converter or planetary gears at all, but this would require a mechanical clutch to switch the power transmission path when changing gears. It is difficult to perform the switching operation smoothly, and there is a drawback that the shock during gear shifting tends to be large. On the other hand, JP-A-56-
The invention described in Publication No. 127841 has a torque converter in addition to a double clutch device, making the configuration complicated and expensive.Moreover, since the clutch devices are not assembled in one place, the overall shape of the transmission and There were some difficulties in making it more compact. Furthermore, in the invention described in Japanese Patent Application Laid-Open No. 56-127842, the double clutch device is not integrated in one place, so there is a problem that the transmission becomes unnecessarily large.

The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and its purpose is to make only slight improvements to conventional mechanical manual transmissions of the constant mesh type. , to obtain an automatic transmission. Another object is to smoothly switch the power transmission path during gear shifting by alternately and gradually engaging and engaging a double clutch device that uses fluid pressure, thereby eliminating the need for gear shifting shocks. Still another object is to provide a dual clutch device within a single clutch housing with the clutch discs adjacent to each other, thereby creating an automatic transmission that is similar in shape and size to a conventional manual transmission. The objective is to make it as compact as a transmission.

In short, the present invention provides a constantly meshing transmission equipped with a first input shaft, a first countershaft, and a main shaft. a second input shaft;
a hollow second countershaft rotatably fitted into the first countershaft;
A first counter gear formed by meshing a second input gear fixed to the input shaft and a first counter gear fixed to the first counter shaft.
a second input gear train formed by meshing a first input gear fixed to the first input shaft and a second counter gear fixed to the second counter shaft; , a first output gear train driven by the first input gear train, a second output gear train driven by the second input gear train, and selectively rotating the output gear trains. a plurality of dog clutches selectively transmitting the engine rotation to the main shaft; and a plurality of dog clutches selectively transmitting engine rotation to the first input shaft or the second input shaft during normal operation and transmitting the rotation of the engine to the first input shaft or the second input shaft during gear shifting. and a double clutch device configured to switch the power transmission path by gradually weakening the power transmission force to one input shaft and gradually increasing the power transmission force to the other input shaft, The dual clutch device is characterized in that each clutch disc is disposed adjacent to the other within a single clutch housing.

The present invention will be explained below based on embodiments shown in the drawings. Automatic transmission AT according to the present invention
In FIGS. 1 and 2, a first input shaft 1, a first countershaft 2,
A constantly meshing transmission comprising a main shaft 3, a hollow second input shaft 4, and a hollow second countershaft 5.
, a first input gear train 6, a second input gear train 8, and a first output gear train 9.
, a second output gear train 10 , a plurality of dog clutches 11 , 12 , 13 , and a double clutch device 14 .

The first input shaft 1 has one end 1a supported by a bearing 18 provided at the rotation center of a ring gear 16 housed in a clutch housing 15, and the other end 1b supported by a transmission case 1.
It is supported together with the second input shaft 4 by a bearing 20 provided at the spline 1.
c and the first input gear 21 are integrally fixedly formed. Also, an oil hole 1d is formed in the center.

The first countershaft 2 is supported and attached to the transmission case 19 by bearings 23 and 24, and includes a first counter gear 26, a third speed gear 28, and a first speed gear. 2
9 and a reverse gear 30 are fixed integrally or by means such as a key 31. As shown in FIG. 2, the reverse gear 30 has shafts 33 arranged in parallel.
Two idle gears 34 are rotatably inserted into the
The second idle gear 36 meshes with a reverse main gear 38.

The main shaft 3 is supported by a bearing 40 disposed at one end 1b of the first input shaft 1 and a bearing 41 of the transmission case 19, and the one end 3b is connected to a propeller shaft (not shown). Splines 3c, 3d, and 3e are formed, and the spline 3c has a dog clutch 11 for selecting third speed or fourth speed, the spline 3d has a dog clutch 12 for selecting first speed or second speed, and Reverse dog clutches 13 are attached to the splines 3e so as to be restrained in their respective rotational directions and rotate integrally with the main shaft 3. Further, a third speed main gear 43, a second speed main gear 44, a first speed main gear 45, and a reverse main gear 38 are rotatably fitted.

The hollow second input shaft 4 is fitted into the first input shaft 1 and supported by the first input shaft 1 through a needle bearing 48 and a bearing 49, and is further connected to the transformer through a bearing 20. It is supported by a transmission 19, and a spline 4c and a second input gear 50 are integrally fixedly formed.

The hollow second countershaft 5 is rotatably fitted into the first countershaft 2.
It is supported by the first countershaft 2 via a needle bearing 51, and a second counter gear 52 and a second speed gear 53 are integrally fixedly formed.

The first input gear train 6 is formed by meshing a second input gear 50 fixed to the second input shaft 4 and a first counter gear 26 fixed to the first countershaft 2.

The second input gear train 8 is formed by meshing a first input gear 21 fixed to the first input shaft 1 and a second counter gear 52 fixed to the second countershaft 5.

The first output gear train 9 is a gear train driven by the first input gear train 6, and includes:
A third speed gear 28 that rotates integrally with the first countershaft 2 and a third speed main gear 43 that meshes with this, a first speed gear 29 and a first speed main gear 45 that meshes with this, Reverse gear 30 and idle gear 34 (first
Idle gear 35 and second idle gear 36)
and a reverse main gear 38 that meshes with the second idle gear 36.

The second output gear train 10 is a gear train driven by the second input gear train 8, and includes a second speed gear 53 and a second speed main gear 44 that meshes with the second speed gear 53.

The dog clutches 11, 12, and 13 are configured to selectively transmit rotation of the first and second output gear trains 9, 10 to the main shaft 3, and each clutch is integrally connected to the main shaft 3. They are attached to rotate, and each is equipped with a synchronizing mechanism S. The clutch sleeve 11a of the dog clutch 11 is made of shifter oak 55.
However, the clutch sleeve 12 of the dog clutch 12
Shifter Oak 56 is in a, Dog Clutch 1
Shifter oaks 57 are engaged with the clutch sleeves 13a of No. 3, respectively, and the shifter rods 58 are
Only one is shown, but it is for 1st speed and 2nd speed,
A total of three gears, one for 3rd and 4th gears and one for reverse, are arranged in parallel so that they can slide freely one after the other, and shifting is performed by the shift arm 60 swinging around the select shaft 61. , selection is performed by moving the select shaft 61 in its axial direction, and all of these are automatically performed by a hydraulic cylinder or the like (not shown) operated by an automatic transmission control device (not shown). It is becoming more and more manipulated.

The double clutch device 14 selectively transmits the rotation of the engine (not shown) to the first input shaft 1 or the second input shaft 4 during normal operation, and transmits the rotation of the engine to the first input shaft 1 or the second input shaft 4 during shifting. The power transmission path is switched by gradually weakening the power transmission force to the input shaft 1 or 4 and gradually increasing the power transmission force to the other input shaft 1 or 4. The clutch 63 includes a first input shaft 1 which is rotated integrally with the first input shaft 1 by a spline 1c.
The first piston 66 is actuated by hydraulic pressure to press the clutch disk against a drive-side rotating body 65 that is integrated with the ring gear 16. Also, the second clutch 6
8 is actuated by a second clutch disk 69 which is integrally rotated by a spline 4c with the second input shaft 4, and a second clutch disk 69 which is operated by hydraulic pressure;
and a second piston 70 that presses the clutch disk against the drive-side rotating body 65.

Also, in the present invention, this double clutch device 14 is provided in a single clutch housing 15.
The clutch disks 64 and 69 are arranged adjacent to each other to achieve compactness.

The present invention is configured as described above, and its operation will be explained below. 1 and 3, firstly, the first speed running state will be described. As shown by arrow A, power is transmitted from the engine from the crankshaft 72 to the drive side rotating body 65 via the ring gear 16. The dog clutch 12 is connected to a first speed main gear 45. When the driver depresses the accelerator pedal (not shown) to start the vehicle (not shown), the automatic transmission control device operates and the drive side rotating body 6
Hydraulic pressure is supplied to the piston 70 from the oil hole 65b provided in the second clutch 68.
The second clutch disk 69 is gradually pressed against the drive side rotating body 65, the clutch disk 69 is gradually accelerated, and the second clutch 68 is connected. (In FIGS. 3 to 6, the state in which the first and second clutches 63 and 68 are disengaged is indicated by "white".
The half-clutched state is shown by "parallel diagonal lines" and the fully connected state is shown by "mesh". In addition, the states where each part is stopped and simply idling are shown as ``thin solid lines,'' the idling states in the preparation stage for power transmission and the power transmission state with a half-clutch are shown as ``broken lines,'' and the state of complete power transmission is shown as ``thick solid lines.'' ) Thereby, the second input shaft 4, the first input gear train 6, (the second input gear 50 and the first counter gear 26), the first counter shaft 2, the first output gear train 9 (1st speed gear 29 and 1st speed main gear 45) rotate while being gradually accelerated, and this increased rotation is transmitted from the dog clutch 12 to the main shaft 3, and power is transmitted to the propeller shaft as shown by arrow B.
The vehicle starts smoothly and accelerates. During this time, the third output gear train 9 constituting the first output gear train 9
The speed gear 28, the third speed main gear 43, the reverse gear 30, the two idle gears 34, and the reverse main gear 38 are idle, and the clutch disk 64 of the first clutch 63 and the first input shaft 1. Second input gear train 8
(first input gear 21 and second counter gear 52), second counter shaft 5 and second
The output gear train 10 (second speed gear 53 and second speed main gear 44) is stopped.

Next, when the vehicle speed gradually increases while the vehicle is running in the first gear and the load on the engine becomes lighter, the automatic transmission control device performs a shift operation to the second gear.
This will be explained with reference to the drawings and FIGS. 4 to 6. First, as shown in FIG. 4, the second clutch 68, first input gear train 6, and first output gear train 9 are driven to the same state as in FIG.
In addition, the dog clutch 11 is connected to the second speed main gear 44. As a result, the second speed main gear 44 idles at the same speed as the main shaft 3, and similarly the second speed gear 53, second counter gear 52, first input gear 21, and first input shaft 1 And the clutch disk 64 spins idly. The rotational speed of the clutch disk 64 is naturally slower than the rotational speed of the clutch disk 69. Therefore, in this state, the second
quickly disengage the first clutch 68 and
3, the second input gear train 8, driven by the clutch disk 64,
output gear train 10 and main shaft 3
Since the speed is rapidly accelerated, the vehicle suddenly accelerates for a moment immediately after being shifted to the second speed, which is undesirable.

In order to prevent this and smoothly shift from the first speed to the second speed, the double clutch device 14 is operated as follows.

That is, as shown in FIG.
8 to a half-clutch state, gradually slow down the rotational speed of the clutch disk 69, and at the same time gradually tighten the first clutch 63 with a large force to bring it into a half-clutched state, and gradually increase the rotational speed of the clutch disk 64. As a result, when the rotational speeds of both clutch disks 64 and 69 match, the power transmission path is smoothly converted.

Then, as shown in Fig. 6, the dog clutch 1
2 from the first speed main gear 45, the first clutch 63 is fully connected, and the second clutch 68
When completely cut, the first input shaft 1,
Power transmission for the second speed is carried out in the power transmission path between the second input gear train 8 and the second output gear train 10, and the vehicle smoothly shifts to the second speed and runs. .

Furthermore, although not shown in the figure, from second gear to third gear
To shift to high speed driving, connect the dog clutch 12 to the third gear main gear 43 from the state shown in FIG. When the dog clutch 11 is tightened and released from the second speed main gear 44, the rotation of the drive side rotating body 65 is transmitted to the second clutch 68 without shock, and the second clutch 11 is released from the second speed main gear 44.
Power is transmitted from the input shaft 4 through the first input gear train 6, the first countershaft 2, the third speed gear 28, the third speed main gear 43, the dog clutch 12, and the main shaft 3 as shown by arrow B. The signal is transmitted to the propeller shaft, and the vehicle smoothly shifts to third gear.

Finally, connect the dog clutch 11 to the first input shaft 1, and then gradually loosen the second clutch 68 while connecting the first clutch 68.
When the dog clutch 12 is separated from the third-speed main gear 43 by gradually tightening the clutch 3 with a larger force, the rotation of the drive-side rotary body 65 is transmitted to the first clutch 63 without shock, and the rotation is transferred to the first input shaft. 1 through the dog clutch 11, and the vehicle smoothly shifts to fourth speed.

Further, the above-mentioned speed change is performed smoothly even during deceleration.

When selecting reverse, after manually connecting the dog clutch 13 to the reverse main gear 38 from the state shown in FIG. 2, and then depressing the accelerator pedal, the second clutch 68 is automatically connected. The rotation of the drive-side rotating body 65 is controlled by a clutch disk 68, a first input gear train 6,
First countershaft 2, reverse gear 3
0, first idle gear 35, second idle gear 3
6. The signal is transmitted to the propeller shaft via the reverse main gear 38, dog clutch 13, and main shaft 3, allowing the vehicle to move smoothly backward.

In each of the above cases, in order to engage and disengage the double clutch device 14, it is sufficient to send oil to the oil holes 65a and 65b to operate the pistons 66 and 70, respectively, and the oil pressure is controlled by the automatic transmission control device. conduct. Therefore, the force for pressing the clutch disks 64 and 69 against the drive-side rotating body 65 can be obtained arbitrarily, and even a delicate half-clutch state can be sufficiently realized. The switching on/off occurs smoothly without any shock.

Also select shaft 61 and shifter rod 5
8 is actuated at desired timing by an air cylinder or hydraulic cylinder controlled by an automatic transmission control device to move each shifter oak 55, 56 and 57.

In the above embodiment, there are four forward speeds and one reverse speed.
Although the description has been made regarding automatic transmission AT, the present invention is not limited to this gear, but is applicable to all mechanical transmissions such as 5-speed, 6-speed, 7-speed, and 8-speed forward transmissions. It goes without saying that it can be done.

Since the present invention is constructed and operates as described above, it is possible to obtain an automatic speed change transmission by making only slight improvements to a normal mechanical manual speed change transmission of a constant mesh type. It has the advantage of being able to In addition, a double clutch device that uses fluid pressure is used to alternately and gradually engage and connect the power transmission path during gear shifting, making it possible to switch the power transmission path smoothly and eliminating the need for gear shifting shocks. can get. Furthermore, a double clutch device is arranged within a single clutch housing so that the clutch discs are adjacent to each other, so although it is an automatic transmission, it is similar in shape and size to a conventional manual transmission. It has the effect of being compact.

[Brief explanation of drawings]

The drawings relate to embodiments of the present invention, in which FIG. 1 is a longitudinal sectional view of an automatic transmission, and FIGS. 2 to 6 are schematic diagrams of the mechanism of the automatic transmission.
Figure 2 is a schematic diagram of the mechanism in the neutral state, Figure 3 is a schematic diagram of the mechanism when running in first gear, Figure 4 is a schematic diagram of the mechanism showing the preparation stage for shifting from first gear to second gear, and Figure 5 is a schematic diagram of the mechanism in the neutral state.
The figure is a schematic view of the mechanism showing a half-clutch state when shifting from first speed to second speed, and FIG. 6 is a schematic view of the mechanism showing a state where the shift to second speed is completed. 1 is a first input shaft, 2 is a first countershaft, 3 is a main shaft, 4 is a hollow second input shaft, 5 is a hollow second countershaft, and 6 is a first input gear. 8 is a second input gear train, 9 is a first output gear train, 10 is a second output gear train, 11, 12, 13 are dog clutches, 14
1 is a double clutch device, 15 is a clutch housing, 21 is a first input gear, 26 is a first counter gear, 50 is a second input gear, 5
2 is a second counter gear, 64 and 69 are clutch disks, and AT is an automatic transmission.

Claims (1)

[Claims] 1. In a constantly meshing transmission equipped with a first input shaft, a first countershaft, and a main shaft, a hollow second shaft is rotatably fitted into the first input shaft. an input shaft, a hollow second countershaft rotatably fitted into the first countershaft, a second input gear fixed to the second input shaft, and the first countershaft.
a first input gear train formed by meshing with a first counter gear fixed to a counter shaft; a first input gear fixed to the first input shaft and fixed to the second counter shaft; a second input gear train in mesh with a second counter gear, a first output gear train driven by the first input gear train, and a first output gear train driven by the second input gear train. a second output gear train, a plurality of dog clutches configured to selectively select and transmit the rotation of each of the output gear trains to the main shaft; Normally, power is transmitted to the second input shaft alternatively, and during gear shifting, the power transmission force to one input shaft is gradually weakened while the power transmission force to the other input shaft is gradually strengthened. a double clutch device which is actuated to switch the power transmission path, and the double clutch device has respective clutch discs disposed adjacent to each other within a single clutch housing. Features automatic transmission.