JPH04165153A - Lock-up provided torque converter for construction vehicle and speed change method thereof - Google Patents

Abstract

PURPOSE:To prevent power loss and perform the selection of an optimum speed stage and a lock-up range by automatic speed change by forming a lock-up of multistage speed change mechanism, and performing a transmission speed change shift in a torque converter range and then performing lock-up speed change. CONSTITUTION:A torque converter body 30 is provided with a two-stage speed reducing lock-up 38, and there are provided a ring gear 42, a sun gear 43 and a planetary gear 44 separable from a lock-up clutch 39, a low clutch 40 and a high clutch 41. The output from a torque converter 30 is transmitted to a transmission through an output shaft 45. Heavy load is thus corresponded to by lock-up driving in order to prevent the power loss of the torque converter 30, and the change-over with torque converter driving and speed change are performed in a torque converter range to make the change-over smooth. In addition, the change-over and speed change are performed automatically according to load fluctuation so as to improve work performance and operability.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a power transmission device, particularly a lock-up mechanism torque converter vehicle of a construction vehicle, which prevents the fluid coupling of the torque converter from being temporarily disconnected during a gear shift. The present invention also relates to a torque converter with a lock-up mechanism and a transmission method for a construction vehicle, which is equipped with a torque converter with a multi-speed lock-up mechanism that automatically switches between the lock-up and torque converter ranges and shifts the optimum speed according to the work load.

[Conventional technology]

Conventional power transmission devices for construction vehicles include a direct drive type equipped with a mechanical clutch and a fluid drive type equipped with a torque converter.With the direct drive type, the engine stops when an overload is applied, and the gear shift operation becomes difficult. Although it has the disadvantage of being poor, it has the advantage of good power transmission efficiency (and being able to transmit power impulsively).

Further, in the fluid drive type, the engine does not stop even when an overload is applied, and the speed change operation is easy, but on the other hand, the power transmission efficiency is poor, and there is a problem that power cannot be transmitted in a shocking manner.

Of course, a torque converter with a two-quanop mechanism has appeared that takes advantage of the advantages of the direct drive type and fluid drive type and eliminates the disadvantages, and recently construction vehicles such as bulldozers are equipped with such a torque converter with a lockup mechanism. are increasing. FIG. 6 shows a power transmission system of a tracked vehicle equipped with the above-mentioned jff pull-up torque converter, in which the output shaft 2 of the engine 1 is input to the torque converter 3. The pump 4 of this torque converter 3 is directly connected to the output shaft 2 of the engine 1, and the stator 5 is attached to a stator shaft 6 that is rotatable with respect to the output shaft 2.
Further, the turbine 7 is directly connected to an input shaft 9 of a transmission 8.

Reference numeral 10 indicates a lock-up of the torque converter 3, and the clutch 11 of the lock-up mechanism 10 is pressed in the direction of the release position by a plurality of springs, and fluid pressure acts to push the operating piston and turn the clutch 11 "on". When in this state, the torque converter 3 is bypassed and the output shaft 2 of the engine 1 is directly connected. The output shaft 12 of the torque converter 3 is connected to the input shaft 9 of the transmissive controller 8 via a joint 13. The transmission 8 is a planetary gear wet type multi-disc clutch type transmission, and has a forward clutch 1.
It is equipped with 5.1-speed clutch, 16.2-speed clutch, 17.3-speed clutch 18, and its output shaft 19 rotates at three forward and forward speeds. The output shaft 19 is transmitted to a horizontal shaft 22 via a pinion 20 and a bell gear 21, and the horizontal shaft 22 is connected to a pair of left and right steering clutches and brakes 2.
3R124R123L, 241= to the pair of left and right final reduction mechanisms 25R, 25L, and these output shafts 26R126L are connected to sprockets 27 R1271, which drive a pair of left and right crawler tracks.

[Problem to be solved by the invention]

However, in conventional torque converters with lock-up mechanisms, power transmission is not always carried out smoothly when switching from the torque converter range to lock-up, or from lock-up to torque converter, resulting in power being cut off and causing the transmission to shift. It has the disadvantage of not being able to absorb the impact when upshifting or downshifting.Moreover, bulldozers must shift to an appropriate speed gear for load fluctuations during dozing, but this shift is selected by the operator. At the same time, the torque converter and lockup had to be mutually switched, and since the interlocking switching was not possible, there was a problem that the speed gear was inappropriate for the work load and work efficiency deteriorated. The work performance per fuel consumption was reduced due to power loss when switching between lock-up and lock-up.

In order to solve the above-mentioned conventional problems, the present invention provides a multi-speed lockup mechanism while maintaining the performance of the torque converter vehicle, and locks up after shifting in the torque converter range to prevent power interruption. The present invention aims to provide a power transmission device and method for a construction vehicle equipped with a torque converter equipped with a multi-stage lock-up mechanism, which eliminates power loss and also selects the optimum speed stage and lock-up range by automatic shifting. be.

[Means and effects for solving the problems] In order to achieve the above object, the present invention transmits engine output to the input shaft of a transmission that changes the running direction and the running speed stage through an l/lux converter with a lock-up mechanism. In the power transmission device that transmits the output shaft of the transmission engine to the left and right sprockets of the lower traveling body through the steering device, the lockup is constituted by a multi-stage transmission mechanism, and the multi-stage transmission port, noqua, and knob are configured. Attached] - The power transmission device of the construction vehicle equipped with a torque converter is configured to perform gear shifting and lock-up shifting of the transmission in the torque converter range.
・After shifting the transmission transmission shift i by using a shift amplifier or downshifting in the torque converter range, the lock-up shift is performed at each speed stage, so it can handle heavy loads while maintaining torque converter drive performance. During work, the switch is switched to direct drive, which maximizes performance, eliminating power loss, and the multi-stage lock-up allows for smooth switching, and the torque converter and multi-stage lock-up switch, as well as transmission gear shifts, depending on the work load. The present invention provides a lock-up torque converter and a gear shifting method for a construction vehicle that automatically shifts to an appropriate speed gear to reduce work performance and operator fatigue.

〔Example〕

The following is a skeleton diagram of the two-stage transmission of LOWSHi as a first embodiment of the present invention, in particular, without showing a torque converter with a deceleration lock-up mechanism. a pump 32 and a turbine 33 provided on the output shaft 31 side.
The stator 34 is provided between the pump 32 and the turbine 33, and the stator 34 is attached to a stator shaft 35 that is rotatable with respect to the output shaft 31. A stator clutch 37 is provided between the stator shaft 35 and the housing 36. The torque converter main body 30 includes a two-stage reduction lockup 3.
8 is provided, 39 is a lock-up clutch, and 40 is a lock-up clutch.
The LOW clutches 1 and 41 are Hi clutches, and are provided with a ring gear 42, a sun gear 43, and a planetary gear 44 that can be connected to and separated from each of these clutches, and the output from the torque converter 30 is transmitted to the transmission via an output shaft 45. be done. Next, the operation of the two-speed lock-up torque converter will be explained with reference to the diagrams in FIG. 2. Note that the thick line indicates power transmission. Figure (A) shows torque converter drive with lockup in the LOW state.
The stator clutch 37 is turned on, and the power from the input shaft 31 is transmitted to the pump 32, turbine 33, ring gear 42, and planet gear 44, and output from the output shaft 45. The frontage pull-up clutch 39 and the frontage pull-up clutch 41 are in the "off" state.
B) The figure shows LOW lock-up drive from the above-mentioned torque converter drive, with the stator clutch 37 and HI lock-up clutch 39 "off", and the torque converter clutch 39 and 1, and the OW lock-up clutch 40 "on". In this state, power is transmitted to the output shaft 45 via the input shaft 31, lock-up clutch 39, and planetary gear 44. Figure (C) shows the torque converter drive in the Hi lockup state, and shows the lockup clutch 39 and L
When the OW lockup clutch 40 is "disconnected" and the stator clutch 37 and the Hi lockup clutch 41 are "engaged", power is transmitted from the input shaft 31 to the pump 32, turbine 33, ring gear 42, and output shaft 45. Furthermore, the figure (D) shows the Hi-rotary lock-up operation, and when the stator clutch 37 and the LOW rotor-up clutch 40 are turned off, and the lock-up clutch 37 and the H3 lock-up clutch 41 are turned on, the power is transferred to the input shaft. 3
1 to lock-up clutch 39, ring gear 42, H
The signal is transmitted to the output shaft 45 via the i-mirockup clutch 4. Therefore, the torque converter drive, LOW and HI shift lockup drives are switched and operated in the order of (A)-(B)-(C)→(D) in each of the figures. FIG. 3 shows the switching of the above-mentioned two-speed shift lock-up in the 3rd gear of the I-transmission. In the figure, the solid line indicates lock-up drive, the dotted line indicates torque converter drive, and
A3 indicates a switching point between lock-up drive and torque converter drive, and B1 to B3 indicate lock-up shift points between LOW and HI. However, when the load changes from a heavy load state to a light load state during work driving, this performance curve +*:
(1st, torque converter drive) =A I-(
1s t, 1°OW lockup drive) →B→(1s
t,, Hi lockup drive) = A2-<2s, T
-OW ll:l pickup drive) -B 2→(2ND
, t(i lockup drive). In addition, A1
At this point, the lock-up range is switched to the torque converter range, and at this time the lock-up range is in the OW state. Also, at point B1, 1. s t (1-OWo
The system first switches from (pick-up drive) to 1st (torque converter drive), and then switches to 1st (Ifi lock-up drive). The above is a case where the load changes from heavy to light, but when the load changes from light 6;f to heavy, the direction of the arrow is reversed. This pattern is then repeated during the work trip.

FIG. 4 is a skeleton diagram showing a torque converter with a two-stage speed increase lockup according to a second embodiment of the present invention, in which 46 is an input shaft, 47 is a l/lux converter main body, 48 is a stator clutch, and 49 is a two-stage torque converter with lockup. 50 is the 1st shift lockup clutch, 51 is the LOW lockup clutch, and 52 is the I (i lockup clutch), which are actuated by each of these clutches, such as a stator shaft 53, a ring gear 54, a sun gear 55, A planetary gear 56 is provided,
By turning on and off these clutches, the output shaft 5 is
7 is output. These torque converter drives and LO
The procedure for switching the W, HiO pickup drive is the same as in the first embodiment. FIG. 5 further shows a scale (ffl) showing a torque converter with a three-stage lock-up mechanism as a third embodiment of the present invention, in which 58 is an input shaft, 59 is a torque converter main body, 60 is a stator clutch, and 611;
3m shift lockup, 62 lockup clutch,
63 is a 1st lock-up clutch, 64 is a ZND lock-up clutch, and 65 is a 3rd lock-up clutch, and the stator shaft 66, first ring gear 67, and second ring gear 6 are operated by these clutches.
8, a second sun gear 70, a second sun gear 70, a first planetary gear 71, and a second planetary gear 72 are provided, and due to the importance of each clutch, the output shaft 73 is
is output to. These torque converter drive and shift lockup drive are the same as those of the first embodiment described above. Next, construction vehicles, especially bulldozers, equipped with a torque converter with multi-speed lockup such as 2nd or 3rd speed repeatedly move forward and backward while excavating and pushing earth and sand during work, but the The load fluctuates between light and heavy loads, but in response to these load fluctuations, the above-mentioned torque converter drive and multi-speed lock-up drive, as well as the transmission speed shift, are automatically switched to ensure proper and efficient work driving. In this system, automatic gear shifting as shown in FIG. 7 is performed. In the figure, 100 is the body of the bulldozer, 101 is the lower running body, 102 is the blade attached to the front, and 103 is the buckle device attached to the rear, and the power transmission is as shown in Figure 6. The engine I04, the torque converter with multi-speed lockup 105, the transmission control unit 106, the steering device 107
, -) is transmitted to the left sprocket 109 of the traveling body through the final reduction gear 108. In order to detect such fluctuations in the work load of the bulldozer as traction force, a strange gauge or oil pressure gauges 110 and 11 are installed in the blade I02 and the ripper device 1103.
The stress detected by the gauges 109 and 11G is manually inputted to the controller 112, determined according to a preset value, and then applied to the speed range of the transmission 106 and the torque converter 105. A command for switching between torque converter drive and multi-speed lockup drive is output, and the appropriate speed stage and torque converter control for the work load are performed to automatically shift gears.

Note that FIG. 8 shows a schematic flow of automatic gear shifting. In addition to the above-mentioned means, there are various means such as shoe slip control for automatic gear shifting, and this embodiment shows an example thereof, and is not limited thereto.

[Effects of the Invention] Since the present invention is configured as described above, it is possible to maintain the I-Luke converter performance and eliminate the power loss of the torque converter, which is particularly common in vehicles with severe load fluctuations such as construction vehicles. The lock-up drive handles heavy loads, and switching to and from the 1-torque converter drive and shifting are performed in the torque converter range, making switching smooth. Furthermore, the above-mentioned switching and gear shifting can be performed manually according to load fluctuations, greatly contributing to improved work efficiency and productivity, regardless of the operator's inexperience, and greatly reducing fatigue. become.

[Brief explanation of drawings]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a skeleton diagram of a torque converter with two-stage reduction lock-up, and FIG. 2 is a skeleton diagram showing the speed change operation of the torque converter. Figure 3 is an explanatory diagram of the transmission and transmission in 3rd gear; Figure 4 is a skeleton diagram of the torque 21 transmission with two-speed lockup as the second embodiment; Figure 5 is a three-speed transmission as the third embodiment. 6 is a schematic diagram showing automatic shifting of a construction vehicle equipped with a multi-speed torque converter with lock-up according to the present invention; FIG. 7 is a flowchart of the same automatic shifting; FIG. 8 is a power transmission skeleton diagram of a construction vehicle, especially a bulldozer. 30.47.59...Torque converter body 31.4
6.58...Input shaft 35.53...Stator shaft 37.48.60...Stator clutch 38...2-stage reduction lock-up 39.50.62...Lock-up clutch 40.51
・・LOW ROSOKUANOBUKURASODI 41.52・ ・Hi
Miroku up clutch 4.54.67.68...Ring gear 43.55.69.70...Sun gear 44.56.71.72...Planetary gear 45.57.73...Output shaft 100...Bulldozer 101 ... Lower traveling body 102 ... Blade 103 ... Ripper device 104 ... Engine 105 ... Torque converter 106 ... Transmission +07 ... Steering device 108 ... Final reduction device 109 ...・Sprocket 110, l], 1...Oil pressure gauge 42...Controller

Claims (3)

[Claims] (1) Engine output is transmitted via a lock-up torque converter to the input shaft of a transmission that changes the running direction and speed, and the output of the transmission is transmitted via a steering device to the left and right sprockets of the lower traveling body. 1. A torque converter with a lockup for a construction vehicle, wherein the lockup is configured by a multi-stage transmission mechanism in the power transmission device. (2) In a power transmission device comprising a torque converter with a lockup and equipped with the above-mentioned multi-stage transmission mechanism, the gear shift of the transmission and the lockup shift are performed in the torque converter range, and the transmission gear shift is performed in the torque converter range. 1. A method of shifting a construction vehicle, characterized in that after shifting up or down to change gears, a lock-up shift is performed at each speed stage. (3) Claim (2) characterized in that the switching between the torque converter drive and the multi-stage shift lock-up drive, and the multi-stage shift lock-up and the transmission speed change are automatically switched according to the work load. How to shift the construction vehicle described.