JPS6319216Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The present invention is designed to move along a tobacco cultivation ridge or a tea cultivation ridge while straddling the ridge.
The present invention relates to a traveling drive device that is equipped with a hydraulic pump that drives traveling wheels and that travels and moves using hydraulic driving force in an agricultural vehicle that performs elevated agricultural work such as sowing, seedling planting, and harvesting.

"Prior art" Conventionally, as shown in Japanese Patent Application Laid-Open No. 126336/1982, 2
A technology was developed to drive the vehicle by installing two hydraulic pumps.

``Problems to be solved by the invention'' However, in the prior art, two hydraulic pumps were directly connected to the engine via a clutch, etc., so by arranging the hydraulic pumps close to the engine, Although the drive structure of the hydraulic pump was easily obtained, the installation position of the hydraulic pump was significantly restricted by the engine installation position, and there was a need for a travel gear lever connection structure or a hydraulic oil tank installation structure to adjust the discharge amount of the hydraulic pump. In addition, if the hydraulic pump is installed at a location distant from the engine, the drive structure of the hydraulic pump cannot be easily simplified, and the drive torque of the hydraulic pump cannot be easily stabilized. There were structural and functional problems such as difficulty in obtaining the desired results.

``Means for Solving the Problems'' However, in the present invention, two hydraulic pumps are installed oppositely on the same bracket, a charge pump is installed on the bracket, and the output pulley of the engine is connected to the pump.
The PTO transmission case is permanently connected to the drive pulley of the PTO transmission case via a belt, and the PTO transmission case is disposed between the engine installation position and the bracket installation position, and the hydraulic pump 1 is installed between the two hydraulic pumps. The present invention is characterized in that two drive pulleys and a charge pump drive pulley are always connected to the drive pulley of the PTO transmission case via a belt.

``Operation'' Therefore, since the two hydraulic pumps and the charge pump are driven via the drive pulley of the PTO transmission case, it is possible to eliminate the problem that the installation positions of the hydraulic pump and the charge pump are restricted by the engine installation position, and also Since the belt on the transmission case side is used, even if the hydraulic pump and charge pump are installed apart from the engine, the hydraulic pump and charge pump can be driven with a belt that is much shorter than the distance between them, and they can be moved away from the engine. The drive torque of the hydraulic pump and charge pump can be obtained more stably than before, and it is also easier to simplify the drive structure of the hydraulic pump and charge pump, as well as the structure related to the hydraulic pump, such as the travel gear lever connection structure or the work oil tank installation structure. The hydraulic travel drive structure can be simplified and the hydraulic travel function can be improved more easily than in the past.

"Embodiments" Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Fig. 1 is an overall left side view of the elevated agricultural vehicle, and Fig. 2 is a plan view of the entire elevated vehicle. a torso body frame 4, 4 whose front end side is swingably attached and connected to the front body frame 1;
6 is a front axle case which is slidably attached to and detachable from both ends of the front body frame 1 via positioning pins 5;
7 is a front wheel mounted on the lower end of the front axle case 4, 4; 8, 9 is a left and right front wheel drive hydraulic motor attached to the upper end of the front axle case 4, 4 via a reduction gear case 10; 11; Reference numeral 11 denotes a rear axle case that is slidably attached to and detachable from both ends of the rear body frame 2 via positioning pins 12; 13 and 14 denote left and right rear wheels that are mounted on the lower ends of the rear axle cases 11 and 11; 15 and 16 17 is a hydraulic motor for driving the left and right rear wheels, which is attached to the upper end of the rear axle cases 11, 11 via the reduction gear case 10, 10, and 17 is an engine 17a installed between the front and rear wheels 6, 13 on the outside of the left side body frame 3. 18 is an engine section to be mounted; 18 is a driving operation section in which a driving frame 19 is fixed between the front and rear wheels 7 and 14 on the outside of the right side body frame 3; and 22 is a driving operation section equipped with a driver's seat 20, a steering wheel 21, etc.; Battery storage room installed below, 2
2 and 24 are right and left row hydraulic motors 9, 16, and 8 mounted in the center of the front part of the body frame 3;
15 two hydraulic pumps for operation; 25 a hydraulic charge pump linked to the hydraulic pumps 23 and 24 via a belt; 26 the engine 17;
a and hydraulic pumps 23, 24, 25
PTO transmission case interlocked with, 27
29 is a PTO housing for taking out the rear PTO which is detachably and directionally connected to the PTO output shaft 28 on the rear side of the transmission case 26; 29 is a traveling gear shift lever which is connected to the hydraulic pumps 23 and 24 to perform traveling gear shifting operations; 30; is the PTO transmission case 2
5 is a PTO gear shift lever, 31 is a hydraulic lift provided approximately at the center of the rear body frame 2 and has a lift arm 32, and 33 is a hydraulic elevator that is pulled to the rear of the aircraft via a lower link 34 and a top link 35, and is equipped with a rotary 36. This is a rotary tilling machine, and is configured to run over tobacco cultivation ridges, tea cultivation ridges, etc., and to perform tillage work using the working machine 33.

FIG. 3 is a hydraulic circuit diagram, in which the variable displacement hydraulic pump 24 is connected to the front and rear wheels 6, which are disposed on the left row of the machine.
13 hydraulic motors 8 and 15 are connected in parallel, and the hydraulic pressure supply to the hydraulic motors 8 is appropriately cut off between these hydraulic motors 8 and 15. One of the two-position and four-port manual hydraulic switching systems is used for switching between 2-wheel drive and 4-wheel drive. A valve 37 is provided. In addition, the other variable displacement hydraulic pump 2
3, the hydraulic motors 9 and 16 of the running wheels 7 and 14 arranged on the right row of the fuselage are connected in parallel, and the hydraulic pressure supply to the hydraulic motor 9 is appropriately cut off between these hydraulic motors 9 and 16. The other 2 for switching drive
A 4-port manual hydraulic switching valve 38 is provided.

Further, between the circuits of the hydraulic motor 15 and the switching valve 37 and the hydraulic motor 16 and the switching valve 38, the front and rear wheels 6, 13 and 7, 14 on the left and right sides are connected to a differential drive, differential suspension (defroc), or A 3-position, 4-port manual hydraulic switching valve 39, which is a hydraulic valve for switching to an emergency drive interruption state, is provided.

In addition, the switching valves 37 and 38 and the hydraulic motor 8
Shuttle valves 40 and 41 are respectively interposed between the shuttle valves 40 and 9, and a 2-position 4-port manual hydraulic switching valve 43 for freewheeling is installed in the connection circuit between the outlet sides of these shuttle valves 40 and 41 and the hydraulic oil tank 42.
are intervening.

On the other hand, by operating the handle 21, the front wheels 6,
A steering cylinder 44 for performing steering control of No. 7 is connected to a hydraulic oil tank 42 via a power steering circuit 45. Also, a charge pump 25 that supplies hydraulic oil to the hydraulic pumps 23, 24 and the circuit 45, a line filter 46 in the middle of the connection circuit, and a freewheel circuit 47.
and. In addition, 48, 49, 50, 51 are quick couplers, and 52 is the switching valve 37, 38,
43 is a single 2WD/4WD switching operating lever for interlocking operation, and 53 is a travel drive mode switching operating lever for switching the switching valve 39.
The switching valves 37, 38, and 43 are constructed as rotary valves that are assembled into the same cylinder block.

As shown in FIGS. 4 to 7, hydraulic pumps 23 and 24 are arranged and fixed in the front and back on the front upper surface of the body frame 3, and the speed change arms 54 and 54 of each pump 23 and 24 are moved as shown in FIG. It is connected to the speed change lever 29 via the speed change rods 55 and 56, and
A turnbuckle 57 is provided at the middle of the rod 56 between the arms 54, 54, and the rod 56 is formed to be extendable and retractable. Also, a cam shaft 5 into which the flow rate control shafts 58, 58 of the pumps 23, 24 are slidably inserted.
9, 59 are fixed to the outside of each pump 23, 24,
A pin 61 that protrudes through an elongated hole 60 in the axial direction of the camshaft 59 is implanted in the flow control shaft 58, and a variable speed cam 62 is rotatably fitted onto the camshaft 59. The speed change arm 54 is fixed. A cam groove 63 is formed in the speed change cam 62.
is opened, the end of the pin 61 is engaged in the cam groove 63, and the flow rate control shaft 58 is stopped and supported via the pin 61, a running neutral region A, and a gentle slope micro speed region B. , a steeply inclined normal speed range C are formed in the cam groove 63, and when the shift lever 29 is operated, the shift cams 62, 62 are rotated via the shift rods 55, 56, and the cam groove 63,
63 to move the flow control shafts 58, 58 forward and backward, and the hydraulic pumps 23, 2
It is formed so that the discharge flow rate of No. 4 can be adjusted.

Furthermore, as is clear from FIGS. 2, 4, and 5, the left and right front and rear wheels 6, 13 are mounted on the front upper surface of the body frame 3 via receiving brackets 64, 65.
Two hydraulic pumps 24 and 23 for left and right travel drive for the pumps 23 and 14 are disposed facing each other, and a planar V-shaped guide bracket 66 is provided between each of the pumps 23 and 24. The front surfaces of the pumps 23, 24 are fixed in contact with the outer surfaces, and the boss portions 67a of the drive pulleys 67 are engaged and supported by the input shafts 23a, 24a that protrude to the front of the pumps 23, 24. One drive pulley 67 is attached to an intermediate portion of each of the hydraulic pumps 23 and 24 to be installed, and the hydraulic pumps 23 and 24 are driven in conjunction with each other via the drive pulley 67. Further, one side of the guide bracket 66 is extended, and a hydraulic charge pump 2 is attached to the extension of the bracket 66.
5 is fixed, a drive pulley 68 is pivotally supported on the input shaft 25a of the pump 25, and a drive pulley 70 of the PTO transmission case 26 is interlocked and connected to the output pulley 69 of the engine 17a with a V belt 71. The drive pulleys 67 and 68 are interlocked and connected to a drive pulley 70 via a V-belt 72.

As described above, the two hydraulic pumps 23 and 24 are installed oppositely on the same bracket 66, the charge pump 25 is installed on the bracket 66, and the belt 71 is connected to the output pulley 69 of the engine 17a to the drive pulley 70 of the PTO transmission case 26. The PTO is connected at all times through the engine 17a and the bracket 66.
Hydraulic pumps 23 and 24 are provided between two hydraulic pumps 23 and 24 with a transmission case 26 disposed therein.
one drive pulley 67 and charge pump 25 for
The drive pulley 68 for the PTO transmission case 26 is always connected to the drive pulley 70 of the PTO transmission case 26 via a belt 72.

This embodiment is constructed as described above, and when the switching valves 37, 38, 39, and 43 are in the state shown in FIG. 15 and the right column hydraulic motor 9,
16 is in a so-called differential suspension (deflock) state in which the connection circuit with the hydraulic pumps 24 and 16 is cut off.
23 is supplied to the left and right row hydraulic motors 8, 15 and 9, 16, and the pump 23 drives the motors 8, 15, and the pump 24 drives the motors 9, 16 in forward and reverse directions as appropriate. .

When the switching valve 39 is now switched in the direction a by the manual switching operation of the operating lever 53, the hydraulic motors 8 and 15 in the left row, the hydraulic motor 9 in the right row,
The 16 hydraulic pressure supply circuits are brought into communication to create a so-called differential state. And now hydraulic pump 23,2
4. Or, when an abnormality occurs in this hydraulic drive system,
When the switching valve 39 is switched in direction b by manual switching operation of the operating lever 53, the hydraulic outlet of the left row hydraulic motors 8, 15 and the right row hydraulic motors 9, 16 are switched.
The hydraulic inlets of the hydraulic motors 9 and 16 communicate with the hydraulic inlets of the hydraulic motors 8 and 15, respectively, and a closed circuit is formed between these motors 8, 9, 15, and 16, and the hydraulic oil circulates. The motors 8, 9, 15, and 16 are then in a state where they are freely rotated by external force or the like. As a result, the front wheels 6 and 7 and the rear wheels 13 and 14 can be freely rotated and the aircraft can be easily moved by external force without causing the abnormal hydraulic circuit system to cause a hydraulic brake state. It is something that can be done.

In addition, this front and rear wheels 6, 7, 13, 14 drive 4
In the driving state, when the operation lever 52 is operated to switch the switching valves 37, 38, 43, the supply of hydraulic pressure from the hydraulic pumps 23, 24 to the hydraulic motors 8, 9 is cut off, and the left and right front wheels 6, 7 is in a drive stopped state and rotates freely due to external force, etc.
Only the rear wheels 13 and 14 are driven in a two-wheel drive state, and during this state, the hydraulic motors 8 and 9 are connected to each motor 8 and 9 through a switching valve 43 and a drain circuit 43a.
This increases the drain oil pressure of motor 9 and interrupts the motor action of each motor 8 and 9.

Next, when the speed change lever 29 is operated to rotate the speed change cams 62, 62 via the speed change rods 55, 56, when the pin 61 is located in the neutral travel range A of the cam groove 63 of the cam 62, the oil pressure is increased. While the flow rate control shafts 58, 58 of the pumps 23, 24 are stopped and supported to maintain a neutral traveling state, the pin 61 moves to the minute speed range B of the cam groove 63, so that
The flow rate control shaft 58 is advanced or retracted by a small amount, and the hydraulic pump 2
By slightly changing the discharge amount of the cam grooves 3 and 24 and moving forward and backward at an extremely low speed, the normal speed range C of the cam groove 63 is shifted.
The amount of displacement of the flow rate control shaft 58 and the amount of movement of the flow rate control shaft 58 are changed in proportion to the amount of movement of the flow rate control shaft 58, and the flow rate control shaft 58 is moved forward and backward at a general moving speed.

As shown in FIG. 8, when the cam groove 63 having a neutral running range A, a very low speed range B, and a normal speed range C is represented in a cam diagram, in the conventional cam diagram represented by a two-dot chain line, the entire cam groove 63 has a normal speed range. It is parallel to the speed range C, and therefore, in the conventional cam operation of the traveling gear shift lever, this neutral speed range is approximately one point, and the neutral support position of the lever is limited to an extremely narrow range. In the cam groove 63 of the present invention, by forming the traveling neutral region A, the neutral support position of the traveling speed change lever 29 can be set in a wide range, and the operation of adjusting the discharge amount of the hydraulic pumps 23 and 24 by the lever 29 is stabilized. It is something that can be done.

``Effects of the Invention'' As is clear from the above embodiments, the present invention has two hydraulic pumps 23 and 24 installed oppositely on the same bracket 66, a charge pump 25 on the bracket 66, and an output pulley 69 of the engine 17a. It is constantly connected to the drive pulley 70 of the PTO transmission case 26 via a belt 71, and the position where the engine 17a is installed and the bracket 6 are connected at all times.
6 PTO transmission case 26 in the middle of the mounting position
A drive pulley 67 for the hydraulic pumps 23, 24 and a drive pulley 68 for the charge pump 25, which are provided between the two hydraulic pumps 23, 24, are connected to the drive pulley 70 of the PTO transmission case 26 by a belt 72. The drive pulley 7 of the PTO transmission case 26 is
Since the two hydraulic pumps 23, 24 and the charge pump 25 are driven via the
24 and the charge pump 25 are restricted to the mounting position of the engine 17a, and the PTO transmission case 26
Since the side belt 71 is used, the engine 17a
Even if the hydraulic pumps 23, 24 and the charge pump 25 are installed apart from each other, it is possible to drive the hydraulic pumps 23, 24 and the charge pump 25 with the belt 72, which is considerably shorter than the installation distance between them. Also hydraulic pump 23,2
4 and the charge pump 25 can be obtained more stably than before, and the drive structure of the hydraulic pumps 23, 24 and the charge pump 25, the connection structure of the traveling speed change lever 29, or the installation structure of the working oil tank 42, etc. of the hydraulic pump 23, 24 related structures can be easily simplified, and the hydraulic travel drive structure can be simplified and the hydraulic travel function can be easily improved compared to the conventional one, which has practical effects. It is.

[Brief explanation of the drawing]

Fig. 1 is a side view of an elevated agricultural vehicle showing an embodiment of the present invention, Fig. 2 is a plan view of the same, Fig. 3 is a travel drive hydraulic circuit diagram, Fig. 4 is a side view of the main parts, Fig. 5 The figure is a plan view of the main part, Figure 6 is an enlarged sectional view of the same part, and Figure 7 is a plan view of the main part.
The figure is an explanatory diagram of the development, and FIG. 8 is a cam diagram. 17a...Engine, 23, 24...Hydraulic pump,
26...PTO transmission case, 66...bracket, 67, 68, 70...drive pulley, 69...output pulley, 71, 72...belt.

Claims (1)

[Scope of utility model registration request] Two hydraulic pumps 23 on the same bracket 66,
A charge pump 25 is provided on the bracket 66, and the output pulley 69 of the engine 17a is always connected to the drive pulley 70 of the PTO transmission case 26 via a belt 71. The PTO transmission case 26 is arranged in the middle of the bracket 66 mounting position, and the two hydraulic pumps 23, 2
A driving pulley 67 for the hydraulic pumps 23, 24 and a driving pulley 68 for the charge pump 25 provided between the four hydraulic pumps 23 and 25 are always connected to the driving pulley 70 of the PTO transmission case 26 via a belt 72. Travel drive system for agricultural vehicles.