JPH0356754A - Mechanical and hydraulic transmission gear and control method therefor - Google Patents

Abstract

PURPOSE:To simplify a structure by connecting clutch of a mechanical transmission gear and disconnecting a clutch of a hydraulic transmission gear in a range where the rotating speed of an output shaft is higher than a designated value, and minimizing the absorption power of a pump. CONSTITUTION:The power transmission of a mechanical hydraulic transmission gears is such that clutch pressure control valves 45, 46 controlled by a control portion 41 are provided to connect a clutch 51 o a mechanical transmission gear 50 fixed to an input shaft 2 and disconnect a clutch 33 of a hydraulic transmission gear 10 in a range where the rotating speed of an output shaft 35 is higher than a designated value. Further, the discharge capacity of a variable-capacity hydraulic pump 21 is minimized, and power from a power source 1 is transmitted to the output shaft 35 through the mechanical transmission gear 50 having good transmission efficiency. On the other hand, when the rotating speed of the output shaft 35 is lower than a designated value, the clutch 51 of the mechanical transmission gear 50 is disconnected, to transmit power to the output shaft 35 through the hydraulic transmission gear 10. Thus, the structure can be simplified, and the power transmission efficiency can be improved.

Description

[Detailed Description of the Invention] (Industrial field in Icheon) This invention relates to a mechanical hydraulic power transmission system and its control method, and is particularly concerned with a high-speed construction machine such as a wheel-type vanshy 3-bell and a rough terrain crane. Concerning power transmission systems for continuous running. (Conventional technology) Conventionally, the following methods have been commonly used in transmission devices for construction machinery, etc. ■.Mechanical power transmission system ■.Hydraulic power transmission system (H S T ) ■. Mechanical-hydraulic power transmission system (HMT) Among these, the mechanical-hydraulic power transmission system (HMT) is a power split type in which part of the transmitted power is transmitted mechanically and the rest is transmitted hydraulically. Among hydraulic transmissions (hydraulic-mechanical transmission), the output split type as shown in Fig. 18 is well known. Although it is efficient, it is difficult to control the switching between forward and reverse operation.In addition, the hydraulic power transmission method (Fig. 19) allows switching control between forward and reverse operation by changing the discharge capacity of the variable displacement pump 51 and motor 52. On the other hand, the speed can be changed by switching the gears 53 and 54, or the gears 55 and 56, and the clutches 57 and 58, but at high speeds, the tilt angle of the pump 5l becomes large and the discharge flow rate increases, causing the pressure to increase. This has the drawback of increasing loss and decreasing efficiency because the tilting angle of the motor 52 decreases.Therefore, conventionally, mechanical power transmission is mainly performed at high and medium speeds to avoid a decrease in efficiency, and at low speeds The mechanical oil formal power transmission system (Fig. 18), which uses mainly hydraulic power transmission and makes it easy to control switching between forward and reverse operation, is used in many fields.In Fig. 18, the power source An input shaft 62 is connected to the input shaft 6l, and a hydraulic pump drive!I is connected to the middle part of the input shaft 62.
A σI wheel 64 that meshes with the + gear 63 is fixed, and a sun gear 65 of a planetary gear system A is fixed to the end. This pressure pump drive gear 63 drives a variable displacement pump 66 of a hydraulic transmission device B provided on one side of the input shaft 62, and this variable displacement pump 66 is connected to the input shaft 62. The constant displacement motors 67 arranged in parallel in the axial direction are operated. A hydraulic transmission passive full wheel 68 is provided on the output shaft of the constant displacement motor 67.

The passive gear 68 is connected to drive an inner gear 69a of the planetary gear system A by a gear 69 meshing with it, and the inner ffi gear 69a and the sun gear 65
A planetary gear 70 is provided between the two. The shaft support frame 7l of this planetary gear 70 is connected to the output shaft 72, and 'll
The revolving motion of the l-star car 70, that is, the shaft support frame 7! The rotary motion of the machine is transmitted to a vehicle body 73 of an appropriate construction machine or the like. When the variable displacement pump 66 is in the neutral state, the hydraulic transmission system WB simply performs a braking action, and the internal gear 69
Since a is fixed, the planetary gear system IA functions as a mechanical planetary reducer, and the speed v4 of the output shaft 72 is controlled by the power source 6.
The speed (not shown) of the governor etc. installed in l! 4. It is carried out by means of control. Also, the variable displacement pump 66 is activated 1".
Then, part of the power is transferred to the transmission elements 64, 63, 66, 67,
The transmission elements 68, 69, and 70 are transmitted in this order, and the other part is mechanically transmitted in the order of transmission elements 62, 65, and 70.

However, the conventional mechanical-hydraulic power transmission system described above has the following drawbacks. That is, since the inner white rotation wheel 69a is driven by a constant displacement motor 67, in order to change the output rotation speed from normal rotation to reverse rotation, a variable displacement pump 66 of the same discharge type is used as a hydraulic pump. In addition, since the inner gear 69a must be rotated at a fairly high speed at a certain rotation speed of the output shaft 72, the capacity ratio between the hydraulic pump and the hydraulic motor must be very large, and in practice When selecting such an ith pressure pump and hydraulic motor, it is quite difficult to realize it. Furthermore, since the gears use a planetary gear system, the structure is unnecessarily complex and costs increase. Furthermore, hydraulic transmission system 1
Since the hydraulic pump, hydraulic motor, and planetary gear device that make up the tB are arranged in parallel in the axial direction of the human power shaft 62, there is a drawback that the entire device becomes large. Further, even when the hydraulic circuit is switched to supply the discharge flow rate of the hydraulic pump to another hydraulic actuator of a working machine such as a construction machine, power is constantly transmitted to the output shaft 72.

Even if the output shaft 72 is fixed with a brake etc., the planetary gear 70
, internal gear 69a. The constant displacement motor 67 is rotated via the driven eleven wheels 68, and power is lost due to stirring loss and the like. Another disadvantage is that switching from a hydraulic transmission to a mechanical transmission is complicated and the shock is large. The present invention focuses on the above-mentioned problems and relates to an improvement of the mechanical-hydraulic power transmission system.The purpose of the present invention is (1) to perform only mechanical power transmission during high-speed rotation, so that losses due to hydraulic pressure are almost eliminated. Become a bassero. ■． At low speeds, the change in output rotation speed between forward and reverse rotations can be smoothly controlled; ■. The structure is extremely simple and inexpensive because it does not use a planetary gear system with a complicated mechanism. ■ The entire installation R can be made compact. (2) By switching the hydraulic circuit, the discharge flow rate of the hydraulic pump can be supplied to other actuators, and hydraulic energy can be used without losing extra power.

■ Changes between hydraulic transmissions and mechanical transmissions, as well as between mechanical and hydraulic transmissions, are detected by detecting changes in output rotational speed, throttle opening, shift position, etc. Since the hydraulic pressure to the clutch is controlled by TA, it can be done smoothly and quickly.

(Means for Solving the Problems)'' 2. In order to achieve the J objective, the present invention, in its first invention, provides a
A hydraulic valve that disengages the clutch of the mechanical transmission device based on a signal from the control section and engages the clutch of the hydraulic transmission device to transmit power to the output shaft, and also switches between the pump and the motor based on a signal from the control section. to switch the rotation direction of the output shaft and change the rotational speed of the output shaft to ti.
4 control and the rotational speed of the output shaft is greater than the predetermined value '! A signal from the A control section engages the clutch of the machine type 44 transmission and disengages the clutch of the hydraulic transmission, transmitting power to the output shaft and minimizing the power absorbed by the pump according to a command from the control section. . The second invention, which has the first invention as its main part, is designed to reduce the amount of power absorbed by the pump! ) The swash plate of the pump is actuated to minimize the discharge capacity of the pump, and the hydraulic valve between the pump and the motor is set to neutral, thereby minimizing the discharge pressure of the pump. By switching the other hydraulic valve between the pump and the valve, the pump's hydraulic pressure can be used for other circuits. The mechanical extraction type transmission device according to the fourth invention is! YiI
A switching means for switching the tj-adism, a speed control means for controlling the speed, a detection means for detecting the rotational speed of the output shaft, a signal of the switching means, a signal of the speed control means, a signal of the output shaft detection means. Comparisons are made between mechanical transmission devices and hydraulic transmission devices with @control devices that control the engagement and disengagement of clutches and at least increase and decrease the capacity of pumps or motors. Further, in the fifth invention, there is provided a switching means for switching between forward and backward movement, and a hydraulic valve that switches the rotational direction of the output shaft by a signal from a control section between the pump and the motor, and controls the +1 rotation speed of the output shaft. , a hydraulic valve that is located between the pump and the motor and switches the hydraulic pressure of the pump to another circuit, a speed control means that controls the speeds t and q, a detection means that detects the rotational speed of the output shaft, and a switching means. Comparing the signal, the speed w4 control means signal, and the output information detection means signal, engaging and disengaging the clutches of the mechanical transmission W and the hydraulic transmission, and increasing or decreasing at least the capacity of the pump or motor i4
A control device that performs Qm, and a control device that performs Qm. (Function) According to the above-mentioned IJI, a clutch pressure control valve is provided which is controlled by a controller when power is transmitted through a mechanical-hydraulic transmission device, and when the rotational speed of the output shaft is greater than a predetermined value, it is fixed to the input wheel. The clutch of the mechanical transmission device is engaged, the clutch of the hydraulic transmission device is disengaged, or the discharge amount of the pump is minimized, and the power is transmitted to the output shaft using a mechanical transmission device with high transmission efficiency, so that the rotational speed of the output shaft is When the value is smaller than a predetermined value, the clutch of the mechanical transmission device fixed to the input shaft is disengaged, and the power is transmitted to the output shaft using the hydraulic transmission device. Therefore, at high speeds, the power loss can be reduced due to good transmission efficiency, and at low speeds, the output speed between forward and reverse rotations can be smoothly controlled. Furthermore, in the case of the mechanical-hydraulic transmission device according to the present invention, a hydraulic valve is provided between the pump and the motor, and when the rotation speed of the output shaft is changed to tI1rB and the rotational speed of the output shaft is changed to reverse, power is transmitted to the output shaft when the boat is set to a neutral boat. The discharge flow rate of the pump can be used for other hydraulic actuators, etc. Furthermore, when multiple hydraulic valves are provided between the pump and the motor, one hydraulic valve can switch between forward and backward movement and also change the rotation angle of the output shaft by 1411 degrees.
However, with other hydraulic valves, the discharge flow rate of the pump can be used for other hydraulic actuators, etc. Also, lJ the pump and motor! Since it is installed side by side with the i-mechanical transmission, the device can be made smaller. Furthermore, switching between a hydraulic transmission device and a mechanical transmission device, as well as switching within each mechanical and hydraulic transmission device, is controlled by detecting changes in output rotational speed, throttle relation, shift position, etc.i) Since the pressure to the clutch is controlled by the L device, it can be done smoothly and quickly.

(Example) The present invention will be described below with reference to an example shown in the drawings. FIG. 1 is an overall configuration diagram of a mechanical-hydraulic transmission device showing a first embodiment of the present invention. It is configured from device 5o. The hydraulic transmission device 1o is composed of a hydraulic transmission device 120 and a speed increase/deceleration device 3o.
Say 1. ) is rotated by a pump shaft 3 driven by the power from a power source 1 through gears 31 and 32 of a speed increase/reduction gear Wl3o fixed to a shaft 2, and is rotated by a variable displacement hydraulic motor 22 (hereinafter referred to as motor 22). ) is connected to the pump 2l by a pipe 23, a hydraulic valve 24, and a pipe 25, and receives the hydraulic pressure of the pump 21 and outputs force to the motor shaft 26. The moving force of the motor shaft 26 is transferred to the output shaft 35 via a clutch 33 of an increase/decrease gear 130 provided on the motor shaft 26, a rotatably inserted gear 34, and a south wheel 36 fixed to the output shaft 35. I will appear in Clutch 33 is bomb 44
The clutch 33 is engaged and the output shaft 35 is rotated by receiving the hydraulic pressure through the clutch pressure control valve 45 controlled by the control section 41. The hydraulic valve 24 is equipped with switching boats 24a, 24b for forward and backward movement of the vehicle, and a neutral boat 24c, which are returned to the tank 29 when the vehicle is in neutral. Further, a pipe 27 branched from the pipe 23 and an oil jI valve 28 are connected to supply and discharge oil to and drive other hydraulic actuators (8). Further, the pump 2l and the motor 22 are provided with discharge volume control valves 11 and 12, and the discharge volume of the pump 21 and the discharge volume of the motor 22 are changed by commands from the control section 41. A speed sensor 42 is provided on the shaft 2, and a continuity sensor 43 is provided on the output shaft 35 to feed back the rotation speed to $11@841.
The lJl mechanical transmission device 50 has a clutch 5 attached to the shaft 2.
l, gear 52 rotatably inserted into @2, and gear 5
5i IC meshed with 2 and fixed to the output shaft 35
5 3, the hydraulic pressure of the pump 44 is controlled by the $lI control section 41! 4-controlled clutch pressure control valve 46
The power of the power source 1 is output to the output shaft 35 by connecting the clutch 51. The control unit B41 consisting of a controller etc. is provided with a switching means 47 such as a switching lever for switching between forward and backward movement of a construction machine, etc., and a speed control means 48 such as an accelerator pedal for controlling vehicle speed. Valve 45, 4
6, etc., constitutes the control device 40.

Next, the operation of the above structure will be explained.

An example of control operation will be explained according to the flowchart in Figure 2. Note that, for example, (step l00) is abbreviated as 100. At 100, the throttle distance eL is determined from the sensor at each position.
1 shift lever position I L p (R-N, 2nd, 1
st), rotational degree N1 of shaft 2, rotational speed N of output shaft 35
o, and the discharge oil JE I) from the pump 21.
At 10l, it is determined whether or not the lever position Fil L p is at the neutral position N, and if it is N, the data at N time is read at any time at 102. If the answer is 101 and no! At 03, the shift lever position L p is in reverse, IR or l
1st or 1st position of the series is disconnected, and if no, that is, the shift lever position 1! When L p is at the 2nd position of two consecutive positions, at 104, shift information is searched from the data No. et with the soft map showing the noft pattern of the 3rd [i1 (a>(b)). At 105, shift information is searched from the data No. It compares the shift position W command obtained from the processing result with the current gear stage and determines whether to go to the soft down or shift annope area.If there is no change in shift at 105, then 106
Then judge again whether the shift lever position I L p is at 1sL or R, and if it is not at R or 1st, that is, 2n
If it is in step d, the process goes to step 200 and the previous processing result or initial value is output as is. When 106 is in R or lsL, the oil pressure in 107 will be explained later! 2! II
Go to the ll control subroutine. When there is a noft change at 105,! ．． 08 and read the clutch engagement pattern shown in Figure 4. The clutch mooring pattern is shown in Figure 5 (
As shown in the shift timing data in a), the control unit 4l
ilDIl? to clutch pressure control valves 45 and 46? ttM l ca and lcb are changed to connect or disconnect the cranoids 33 and 51. In addition, when there is a noft change, the control i3Il flow lca
Changes between and Icb (T f , T t, Tm, etc.)
is given by the matrix shown in Figure 4 for each speed stage. In l09, Schiff}R conversion is l. s
It is determined whether the change is from t to 2nd, and if it is from lsL to 2nd, it is determined by 111 that the Ti from the till control B41 is changed to the valve 1l for controlling the discharge volume of the pump 2l, as shown in the shift timing data example in FIG. 5(C). Current 1pd and current 1 from illllJfiH41 to hydraulic valve 24
vf is varied with respect to cut-off time t and output at 200.

If it is not 2nd from lsL at +09, go to 110,
Read the start timing of the hydraulic drive routine. The startup timing is as shown in the example of the pump timing data in FIG.
Control to l from i1441? lifilpd, control unit 4 for valve l2 for controlling the discharge volume of the motor 22
tl from l! M to flow 1md and hydraulic valve 24
The subroutine for the hydraulic drive Tll control of the lO7, which causes the change in the current 1 v f from the Ill section 4l to rise after the startup timing Ths and outputs it at 200, is the flow shown in FIG. Find the target engine rotation number Ne for the opening degree et (
Figure 7). In 122, the deviation e1 between the target engine rotation speed Ne and the rotation speed N1 of the shaft 2 is determined, and in 123, the deviation e1 is calculated.
Target absorption torque Tpo of the pump 21 for the opening degree OL
Calculate (Figure 8). In step 124, the absorption torque T p of the pump 21 is calculated taking into account the rotational speed deviation e1, and in step 125
Now, find the discharge volume 9Dp of the pump 21 with respect to the pump oil pressure P when the absorption torque Tp. 126 has a bomb 2l
Find the control current +pd commanded from 'U4 control fl+41 to the discharge capacity control valve 1l so that the discharge capacity becomes the discharge capacity■)p. In step 127, calculate the 'Mm current (2) which is commanded to the pressure valve 24 to flow an amount of fa that matches the running speed with respect to the throttle distance et (Fig. 9).
At 128, it is determined whether the shift lever position Lp is at R, and if not, at 129, the hydraulic valve 2 4 C) i
Give the control current 1v that was determined in step 127 to the control current 1vf of the iii-adic electromagnetic solenoid, and give zero to the tillflffft flow 1vr of the reverse electromagnetic solenoid on the opposite side. Also R
, the till control current 1V calculated in step 127 is given to the control current lvr for reversing in step 130, and zero is given to Ivf. 13l calculates the discharge capacity of the hydraulic motor with respect to the rotational speed No. of the output shaft or the speed of the vehicle (first
Figure 0〉. At 132, the hydraulic motor iqm current 1md is calculated so that the discharge capacity calculated by +31 is obtained. Fig. 11 shows the second embodiment. Identical parts are given the same reference numerals and clarifications are omitted. The 1st has the same structure as the first embodiment, but the 2n
d is connected via a peak 4f 1 3 1 fixed to the motor shaft 26 by a clutch 132 of a bottle reduction gear + 30 provided on the output shaft 35 and a delivery wheel 133 inserted into the rotating shaft. There is. The clutch 132 controls the hydraulic pressure of the pump 44.
The power is received via the clutch pressure control valve 145 controlled by the M'D5 section 141, the clutch 132 is engaged, and the power of the motor shaft 26 is output to the output shaft 35. The 3rd and 4th of the mechanical transmission W150 are 2n of the first embodiment.
The 3rd is configured in the same manner as d, and the 3rd includes a cluff 151 fixed to the shaft 2 of the mechanical transmission 1150, a gear +52 rotatably inserted into the shaft 2, and a gear +52 that meshes with the gear 152 and is fixed to the output shaft 35. Consists of gear 153, pump 44
The hydraulic pressure? 4 through a clutch pressure control valve 146 controlled by a clutch 15 control section 141
1 and outputs the power Ml to the output shaft 35. 4
Similarly, th is controlled by cranometer +161, gear 162, rP wheel 163, and clutch pressure control valve 166. In this case, Kula, Chi+S+,
16+ and gears 152, 162 on the output shaft 35, tooth -1
f l 5 3, 163 may be provided on the shaft 2, or may be provided alternately. Next, the operation of the above structure will be explained according to the flowchart shown in Fig. 12. If the operation is the same as that in the flowchart of FIG. In this embodiment, the shift lever position ILq is R2 for reverse 2nd speed.
, Rl for reverse 1st gear, N for neutral, 1 for forward 1st to 4th gears
,2,3,D. At step 204, search is made for NFF1 information from the data No. and eL using the shift map that follows the shift pattern aligned at Noft Leper position 2Lq in FIG. l05
Then, the soft position {h command obtained from the processing result in step 103 or 204 is compared with the current speed stage, and it is determined whether to go to the soft down or shift up area.

When there is no change in the software at +05, at 206 the current gear position is hydraulic drive position 1st, 2ndSR1s
t. If it is not in R2sL, that is, 3th,
If it is on 4th, just go to 2oO<. I at 206
sL, 2ndXRlsc, and R2SL, subroutine 10 of the hydraulic drive LIAII is the same as in the first embodiment.
Go to 7. In this case, the lth actual y & example sunknob +07 means that the discharge capacity of the pressure motor is the 14th relative to the output shaft rotational speed.
As shown in the figure, 1st, 2nd or R l. s t
, R2st. At this time, the same rotational speed of the motor shaft may be detected instead of the output rotational speed as shown in FIG. When there is a noft change in 105, 20
8 and read the clutch engagement pattern fml6[m]. The clutch engagement pattern is as shown in the shift timing data example of 51ffi (a).
and control voltages 1iWlca, Icb, IcC to 166
, and Icd, the clutch 33,
Join or disconnect any of 132, 15l3 and 161. Oh, $1 when there is a shift change! Changes in control currents lea, Icb, Icc, lcd (Tf.
(Tt, T m, etc.) are calculated using a matrix as shown in Fig. 16 for each speed stage. At 209, it is determined whether the noft change is a direct connection change from hydraulic drive to mechanical transmission 50, and if it is from hydraulic drive to direct connection, noft change is determined at 210.
Pump 2 as shown in the shift timing data example in Figure (C)
Control unit 14 for valve l1 for controlling the discharge volume of l
The current Ipd from 1 and the current 1vr from the tilI control unit 4l to the hydraulic valve 24 are changed with respect to the switching time t, and output at 200. If the change is not from hydraulic drive to mechanical transmission, 211 indicates mechanical transmission 1! It is determined whether the change is a change from +50 to hydraulic drive, and if it is not, it goes to the stenop 200 and outputs it as is. In the case of direct connection, the current 1 from the control 1141 to the valve 11 for controlling the discharge volume of the pump 2I is set at 212, as shown in the shift timing data example of FIG.
pd and the current 1vf from the "#A control part 141 to the hydraulic valve 24 is changed with respect to the switching time t, and is output at 200. In the above embodiment 1, the hydraulically driven gear is 1st gear and 8l gear. Although the drive gear stage is set to one stage, and the hydraulic drive gear stage is set to two stages and the mechanical drive gear stage is set to two stages in Embodiment 2, a combination as shown in Fig. 17 may also be used. Although a 1,211N hydraulic valve is provided between the valves, a large number may be provided, and tandem, Solise, parallel, and combined circuits may also be used for the hydraulic circuit.Furthermore, the hydraulic circuit of the hydraulic drive device may only be an open circuit. As described above, it goes without saying that a closed circuit may be used. (Effects of the Invention) As explained above, according to the present invention, the mechanical transmission device and the hydraulic transmission device of the 8!1 mechanical-hydraulic transmission device In the range where the rotational speed of the output shaft is greater than the specified value, the mechanical transmission device transmits the power, which improves efficiency, and in the range smaller than the specified value, the hydraulic transmission device transmits the power. It is possible to smoothly control the output rotation speed between one rotation and reverse rotation.In addition, switching between the hydraulic transmission system and the transmission system (transmission system), as well as switching within each mechanical and hydraulic transmission 2a, is possible. Output l1I] Changes in rotational speed, throttle angle, noft position, etc. are output, and the hydraulic pressure to the clutch is controlled by a controller, so it can be performed smoothly and quickly.In addition, it is possible to operate smoothly and quickly with a planetary gear system that has a complex mechanism. Since it does not use a hydraulic pump, the structure is simple, compact, and inexpensive.Also, by switching the hydraulic circuit, the discharge flow rate of the hydraulic pump can be supplied to other actuators, so there is no loss of excess power. This provides the excellent effect of being able to utilize hydraulic energy without having to use hydraulic energy.

[Brief explanation of drawings]

FIG. 1 is an overall structural diagram of a mechanical-hydraulic transmission device showing a first embodiment of the present invention. FIG. 2 is a flow chart of the first embodiment of the present invention. Figure 3 (a) shows the output shaft rotational speed, throttle opening, and
Figure (b) is a diagram showing the relationship between output shaft rotational speed and output shaft torque. Figure 4 is a diagram showing the relationship between output shaft rotation speed and output shaft torque. Figure 16 is a diagram showing a clutch engagement pattern. Figure 5 is a diagram showing a time chart of shift timing. Figure 6L4 is a diagram showing the oil pressure. Flowchart 51 for drive control Fig. 7 shows the relationship between throttle opening and target engine rotational speed Fig. 8 shows the relationship between throttle opening and hydraulic pump 1-1 mark and torque output Figure 9 is a diagram showing the direct relationship between the throttle opening and the current flowing to the hydraulic valve (Figure 10 is a diagram showing the direct relationship, and Figure 14 is a diagram showing the relationship between the output shaft rotational speed and the discharge capacity of the bending pressure motor). FIG. 1 is a diagram showing the overall structure of a mechanical pressure transmission device according to a first embodiment of the present invention. FIG. 12 is a flow diagram of the first embodiment of the present invention. Figure 13(a) is a diagram showing the relationship between the output shaft co-rotating speed, throttle opening, output shaft torque, and gear position at each 7-lift position K; Figure W415 is a diagram showing the relationship between the output shaft rotational speed, throttle distance, output shaft torque, and gear stage. Figure M17 is a diagram showing the relationship between the pressure motor shaft rotational speed and the discharge capacity of the hydraulic motor. A diagram showing combinations of gear stages for hydraulic drive and mechanical drive. Fig. 18 is an overall structural diagram of a mechanical-hydraulic transmission device showing an example of a conventional conventional hydraulic power transmission. Overall configuration diagram of the Buddhism system 3 20 21 22 24 30 3 5 3 131, rice cart 3 3, 5 latch power source, 2 shafts, pump shaft 10 Hydraulic transmission device Hydraulic transmission device variable displacement pump Variable displacement hydraulic motor hydraulic valve, 26 Motor shaft speed increase/decrease device 2, 34, 36, 52, 53. ．． l30, 152, 15
3, 162, 163 1, 132, 151.161 ku4 5, 1 4 5, +46, . 166 pressure control valve 40 control device, 41,! 4 1--i! It control section 42, 43 - Speed sensor 47 Switching means 4 Speed A control means 50, 150 - Mechanical transmission clutch

Claims (1)

[Claims] 1) In a mechanical hydraulic transmission device having a power source having a speed control means, a hydraulic transmission device, a control device and a mechanical transmission device, the rotational speed of the output shaft is smaller than a predetermined value. In the range, the clutch of the mechanical transmission is disengaged by a signal from the control unit, and the clutch of the hydraulic transmission is engaged, transmitting power to the output shaft, and the hydraulic pressure is switched between the pump and motor by a signal from the control unit. Operates a valve to switch the rotation direction of the output shaft and control the rotation speed of the output shaft, and engages the clutch of the mechanical transmission device by a signal from the control section when the rotation speed of the output shaft is greater than a predetermined value. A mechanical-hydraulic transmission device and its control method, characterized in that the clutch of the hydraulic transmission device is disengaged to transmit power to an output shaft, and the power absorbed by the pump is minimized by a command from a control section. 2) In order to minimize the power absorbed by the pump, the pump's swash plate is activated by a command from the control unit to minimize the pump's discharge capacity, and the hydraulic valve between the pump and motor is set to neutral. The mechanical-hydraulic transmission device and its control method according to claim 1, wherein the discharge pressure of the transmission device is minimized. 3) The mechanical hydraulic transmission device and its control method according to claim 1), wherein the hydraulic pressure of the pump can also be used for other circuits by switching other hydraulic valves between the pump and the valve. 4) In a mechanical hydraulic transmission device having a power source having a speed control means, a hydraulic transmission device, a control device and a mechanical transmission device, a switching means for switching between forward and backward travel and a speed control means for controlling the speed. , a detection means for detecting the rotational speed of the output shaft, a signal from the switching means, a signal from the speed control means, and a signal from the output shaft detection means to connect the clutches of the mechanical transmission device and the hydraulic transmission device; A mechanical-hydraulic transmission device consisting of a control device for controlling disconnection and increasing or decreasing the capacity of at least a pump or motor. 5) In a mechanical hydraulic transmission device having a power source having a speed control means, a hydraulic transmission device, a control device and a mechanical transmission device, a switching means for switching forward and backward movement, and a control device between the pump and the motor. A hydraulic valve that switches the rotational direction of the output shaft and controls the rotational speed of the output shaft based on a signal from the pump, a hydraulic valve that is located between the pump and the motor that switches the pump's hydraulic pressure to another circuit, and a speed control that controls the speed. means, a detection means for detecting the rotational speed of the output shaft, a signal from the switching means, a signal from the speed control means, and a signal from the detection means for the output shaft; A mechanical-hydraulic transmission device consisting of a control device for controlling disconnection and increasing or decreasing the capacity of at least a pump or motor.