CN102887171B - Riding work machine - Google Patents

Abstract

A riding work machine (10) comprises a steering wheel (31), an engine (11), a hydraulic stepless transmission mechanism (62) for transmitting power of the engine (11) to a driving wheel (14, 14), and a pivotable operation lever (71) for operating the hydraulic stepless transmission mechanism (62) to change the running speed of the work machine (10). A return mechanism for returning the hydraulic stepless transmission mechanism (62) to a position of reducing the running speed of the work machine (10) when the hydraulic stepless transmission mechanism (62) is operated by the operation lever (71) and the steering wheel (31) is turned is mounted at a base (71a) of the operation lever (71).

Description

ride-on work machine

technical field

The invention relates to a ride-on work machine driven by an engine and capable of automatically reducing the traveling speed when turning.

Background technique

Recently, the steering system and the work system of ride-on work machines have been able to work in harmony with each other, so that the work machine can also work safely and efficiently while turning safely. As one of such working machines, agricultural machines are required to have sufficient durability to be able to be used under severe working conditions. In order to provide a work machine such as an agricultural machine with sufficient durability, in Japanese patent applications JP-A-51-42218 and JP-A-57-91414, there is disclosed a machine that does not require the use of an electric control system but only uses a mechanical The system can make the working machine automatically decelerate when the working machine turns.

A ride-on work machine disclosed in Japanese Patent Application JP-A-51-42218 is a tractor having an accelerator lever and left and right steering mechanisms respectively cooperating with a steering wheel. The speed of the engine is adjusted by operating the accelerator lever to cause the accelerator lever to adjust the governor and the fuel injection device. When the steering wheel is turned left or right, the left and right steering mechanisms are driven to control the governor and the fuel injection device through the accelerator rod to decelerate the engine. As a result, the travel speed of the work machine is automatically reduced.

Considering the structure of the working machine, the left and right steering mechanisms must be arranged near the acceleration pull rod. This means that the structure for automatically reducing the traveling speed of the working machine according to the steering of the working machine is rather complicated and bulky. Since the left and right steering mechanisms are arranged near the accelerator rod, the working machine only has a very limited space left for installing other components. In other words, the degree of freedom of installation of other components of the work machine is low. In addition, the mechanism of reducing the engine speed to automatically decelerate according to the steering of the work machine cannot be applied to a ride-on work machine that relies on a single engine to drive both the traveling system and the working system. In other words, the automatic deceleration mechanism for working machines disclosed in Japanese Patent Application JP-A-51-42218 is not suitable for ride-on working machines that rely on a single engine to drive both the traveling system and the working system.

The ride-on work machine disclosed in Japanese Patent Application JP-A-57-91414 includes a gear transmission mechanism for transmitting the output power of the engine to the wheels, a belt-type continuously variable transmission mechanism arranged between the engine and the gear transmission mechanism (belt-type continuously-variable transmission), and a reduction mechanism cooperating with the steering wheel, which is used to control the belt-type continuously variable transmission mechanism to reduce the driving speed of the working machine. Specifically, when the cam (cam) detects that the rotation of the steering wheel exceeds a predetermined angle, the reduction mechanism is activated to control the belt type continuously variable transmission mechanism to reduce the traveling speed of the working machine. As a result, the working machine is automatically decelerated when the working machine turns.

Because the operating machine disclosed by the Japanese patent application JP-A-57-91414 has a belt-type continuously variable transmission mechanism in addition to a gear transmission mechanism, thereby reducing the speed reduction mechanism of the operating machine when the operating machine turns. It inevitably has a complex structure and a huge volume. Furthermore, such a working machine including two transmission mechanisms leaves only very limited space for installing other components. This means that the freedom of installation of other components of the work machine is very low.

Therefore, for the ride-on work machines disclosed by Japanese Patent Applications JP-A-51-42218 and JP-A-57-91414, the complexity of the deceleration mechanism used to reduce the travel speed of the work machine when the work machine turns Structural and bulky are urgent problems to be solved.

patent documents

[Patent Document 1] JP-A-51-42218;

[Patent Document 2] Publication No. 57-91414.

Contents of the invention

The main object of the present invention is to provide a simple mechanism capable of automatically reducing the steering speed for a riding-type work machine driven by a single engine driving a traveling system and a working system.

The invention provides a ride-on work machine, which includes: steering wheel; engine; drive wheel; hydraulic stepless transmission mechanism for transmitting the output power of the engine to the drive wheel; For manipulating the hydraulic continuously variable transmission mechanism to change the driving speed of the working machine, the joystick includes a base; a reset mechanism is used to make the hydraulic continuously variable transmission mechanism operate by the joystick and turn the steering wheel to make the The hydraulic continuously variable transmission mechanism returns to a position for reducing the travel speed of the working machine, wherein the reset mechanism is disposed on the base of the joystick.

A reset mechanism for automatically reducing the traveling speed of the working machine when the working machine turns is provided on the base of the joystick. Since the reset mechanism is provided on the base of the joystick, its structure is simpler than that of a reset mechanism provided independently of the joystick. In addition, since the return mechanism is provided on the base of the joystick, it is possible to easily ensure that the work machine has enough space for installing other parts than the return mechanism, thereby improving the work efficiency. Freedom to install other parts of the machine.

The reset mechanism is suitable for a ride-on working machine with a single engine driving a working system and a traveling system. This is because the deceleration mechanism does not decelerate the engine when the work machine turns, but reduces the travel speed of the work machine, thereby maintaining The working speed of the working system.

The resetting mechanism is driven by turning the steering wheel, so that the hydraulic continuously variable transmission mechanism is returned to the position where the output shaft speed of the hydraulic continuously variable transmission mechanism is reduced through the joystick. As a result, the travel speed of the working machine can likewise be automatically reduced.

In a preferred embodiment of the present invention, the hydraulic continuously variable transmission mechanism includes a transmission control shaft, and the reset mechanism includes: a support member, which is connected to the base of the joystick and can move freely in a certain direction. The joystick swings to change the running speed of the work machine; the swing arm is supported by the support and can swing in the direction in which the support swings; the pull rod is connected with the swing arm and used to control The force of the joystick is transmitted to the transmission control shaft of the hydraulic continuously variable transmission mechanism; and the steering angle transmission mechanism is used to transmit the steering angle turned by the steering wheel to the swing arm, so that the swing arm follows the The steering angle swings.

The reset mechanism has a simple structure, which includes: a support member, which can swing in a certain direction with the joystick so as to manipulate the hydraulic continuously variable transmission mechanism to change the driving speed of the working machine; a swingable swing arm, supported by the support A component support; a pull rod, connected with the swing arm; and a steering angle transmission mechanism, used to transmit the steering angle of the steering wheel to the swing arm.

When the steering wheel is at a position where the work machine travels straight, the steering angle is zero. In this case, since the joystick swings together with the support, the swing arm swings together with the joystick and the support. The swinging action of the swing arm manipulates the transmission control shaft of the hydraulic continuously variable transmission mechanism by means of a pull rod to change the traveling speed of the working machine. When the steering wheel is subsequently turned, the steering angle through which the steering wheel is turned is transmitted to the swing arm by the steering angle transmission mechanism. Afterwards, the swing arm swings relative to the support member according to the steering angle, so as to operate the transmission control shaft of the hydraulic continuously variable transmission mechanism by means of the pull rod, so as to reduce the traveling speed of the working machine.

In another preferred embodiment of the present invention, the steering angle transmission mechanism includes: a steel cable for transmitting the steering angle to the swing arm; and a return spring for pushing the swing arm in a certain direction, In order to adjust the transmission control shaft of the hydraulic continuously variable transmission mechanism back to the position for reducing the travel speed of the working machine.

The steering angle transmission mechanism for transmitting the steering angle to the swing arm includes a steel cable. The beneficial effect brought by this technical feature is that the position of the swing arm relative to the steering wheel is not restricted, thereby improving the installation freedom of the reset mechanism. In addition, the swing arm is always pushed in a certain direction by a return spring to return the transmission control shaft to a position that reduces the travel speed of the working machine. That is, the swing arm is always pushed in a certain direction by the return spring to provide a fail-safe function. Therefore, even if an accident occurs in the steering angle transmission mechanism, the return spring will apply a urging force to the swing arm to swing the swing arm in a certain direction, thereby returning the transmission control shaft to The position to reduce the travel speed of the work machine. Thus, the steering angle transfer mechanism provides an improved fail-safe function.

In the following, preferred embodiments of the present invention will be described in detail by way of example only with reference to the following drawings.

Description of drawings

Fig. 1 is a side view of the ride-on work machine of the present invention;

Fig. 2 is a schematic diagram of the steering system, driving system and reset mechanism in Fig. 1;

Fig. 3 is a sectional view of the steering angle transmission mechanism shown in Fig. 2;

Fig. 4 is an exploded view of the steering angle transmission mechanism shown in Fig. 3;

Fig. 5 is a front view of the steering angle transmission mechanism shown in Fig. 3;

Fig. 6 is a front view of the operating state of the steering angle transmission mechanism shown in Fig. 5;

Fig. 7 is the perspective view of traveling mechanism and reset mechanism;

Fig. 8 is a side view of the reset mechanism shown in Fig. 7;

Figure 9 is a front view of the reset mechanism shown in Figure 8;

Figure 10 is an exploded view of the reset mechanism shown in Figure 8;

Fig. 11 is a schematic diagram showing that the joystick is located at the forward position where the working machine travels at the highest speed;

Figure 12 is a schematic diagram of the reset mechanism shown in Figure 8;

Fig. 13 is a schematic diagram of the reset mechanism shown in Fig. 11 .

Detailed ways

As shown in FIGS. 1 and 2 , the ride-on work machine 10 includes a working system 20 , a steering system 30 and a traveling system 60 . The working machine 10 is driven by a single engine 11 together with a working system 20 . Specifically, the engine 11 drives the working system 20 through one belt, and drives the traveling system 60 through another belt. In this embodiment, the working system 20 includes a mowing unit.

The engine 11 is installed on the upper part of the rear part of the machine body 12 of the working machine 10 . The body 12 is equipped with left and right front wheels 13,13 and left and right rear wheels 14,14. The front wheels 13 and 13 are steered by a steering wheel 31 mounted on the front of the body 12 . The rear wheels 14, 14 are driving wheels driven by the output power of the engine 11.

As shown in FIG. 1 , the mowing part of the handling system 20 is arranged under the middle part of the machine body 12 and includes a cutter 21 driven by the output power of the engine 11 transmitted by the belt. The grass mowing section also includes a lower open cutter compartment 22 for accommodating the cutter 21 . The grass cut by the cutter 21 is sent into the grass storage bag 23 .

The steering system 30 includes a steering wheel 31 for turning the left and right front wheels 13 , 13 . The steering system 30 further includes a steering shaft 32 connected to the steering wheel 31 , a steering gear 33 connected to the steering shaft 32 , and a driving gear 34 meshed with the steering gear 33 . The steering system 30 also includes an intermediate shaft 35 connected to the drive gear 34, a steering rocker (steering arm) 36 connected to the intermediate shaft 35, left and right tie rods 37 connected to the steering rocker 36, 37. Left and right steering knuckle arms 38, 38 and left and right front wheels 13, 13 respectively connected with the left and right tie rods 37, 37. The steering gear 33 is a spur gear. The driving gear 34 is a sector gear.

The steering torque generated by the rotation of the steering wheel 31 passes through the steering shaft 32, the steering gear 33, the driving gear 34, the intermediate shaft 35, the steering rocker arm 36, the left and right tie rods 37, 37 and the left and right steering knuckle arms 38, 38 Pass to the left and right front wheels 13,13. Thus, the left and right front wheels 13, 13 are turned.

As shown in FIG. 2 , the steering system 30 further includes a steering angle transmission mechanism 39 . The steering angle transmission mechanism 39 allows the swing arm 73 to swing according to the steering angle through which the steering wheel 31 is turned. The steering angle transmission mechanism 39 includes a steering angle conversion mechanism 40 , a steel cable 51 and a return spring 57 .

The steering angle conversion mechanism 40 is used to convert the steering angle into linear displacement. As shown in FIGS. 3 to 5 , the steering angle conversion mechanism 40 includes a sliding pin 41 , a connecting pin 42 , a sliding seat 43 , a first arm 44 and a second arm 45 .

The sliding pin 41 and the connecting pin 42 extend parallel to the intermediate shaft 35 . The sliding seat 43 is installed on the body 12 and has an elongated guide portion 43a, which forms a straight long hole (slot) extending in a direction perpendicular to the intermediate shaft 35 . The sliding pin 41 is installed in the linear long hole of the guide part 43a, and can slide in the linear long hole. One end of the first arm 44 is connected to the sliding pin 41 and can slide with the sliding pin 41 . The other end of the first arm 44 is connected to one end of the second arm 45 through the connecting pin 42 , so that the first and second arms 44 , 45 can swing relative to each other. The other end of the second arm 45 is connected to the driving gear 34 .

When the steering angle is 0, that is, when the working machine 10 is running straight, as shown in FIG. 5 , the sliding pin 41 and the connecting pin 42 are located on the first straight line L1. The guide portion 43a extends along the first straight line L1. The sliding pin 41 is located at the linear movement position Ps formed by the end of the guide portion 43 a away from the intermediate shaft 35 .

When the steering wheel 31 is turned rightward, the steering shaft 32 , the steering gear 33 and the driving gear 34 rotate by a certain amount, which is the same as the steering angle by which the steering wheel 31 is turned rightward. The rotation of the driving gear 34 causes the first and second arms 44 , 45 to swing, thereby guiding the sliding pin 41 to move linearly toward the intermediate shaft 35 through the guide portion 43 a. Through the linear movement, the sliding pin 41 reaches the position shown in FIG. 6 . The linear sliding amount or sliding distance of the sliding pin 41 corresponds to the steering angle through which the steering wheel 31 is turned. When the steering wheel 31 is turned to the left, the slide pin 41 slides in the same manner as when the steering wheel 31 is turned to the right. Therefore, the steering angle through which the steering wheel 31 turns can be converted by the steering angle conversion mechanism 40 into the linear movement or linear displacement of the sliding pin 42 .

The ratio of the distance between the intermediate shaft 35 and the connecting pin 42 to the distance between the connecting pin 42 and the slide pin 41 needs to be properly set. This ratio can be set to provide an optimum ratio between the change in the sliding amount of the slide pin 41 and the change in the steering angle through which the steering wheel 31 is turned. The ratio is set as follows: when the steering angle is close to 0, the ratio of the sliding amount change of the sliding pin 41 to the steering angle change is small; The ratio of the change in the sliding amount of the pin 41 to the change in the steering angle is large.

The steel cable 51 includes an outer casing 52 and an inner cable 53 extending inside the outer casing 52 . An end portion 52a of the outer sleeve 52 is connected to the body 12 and located on a first straight line L1 extending along the length direction of the guide portion 43a. Specifically, the end portion 52a of the outer sleeve 52 is disposed closer to the front portion of the body 12 (intermediate shaft 35) than the guide portion 43a. The end portion 52a has an open end 52b facing the rear of the body 12 (a direction away from the intermediate shaft 35).

The inner cable 53 has an exposed end portion 53a, and the exposed end portion 53a protrudes outward from the open end 52b of the end portion 52a of the outer sleeve 52 and extends toward the rear of the body 12 . The exposed end portion 53 a of the inner cable 53 is connected to one end of the first arm 44 through an adapter 54 and a cable connection pin 55 . The cable connecting pin 55 is always vertically aligned with the sliding pin 41 .

In the case of not using the adapter 54 , the sliding pin 41 can be used as the connecting pin 55 to realize the function of the connecting pin 55 .

As shown in FIGS. 1 and 2 , the left and right rear wheels 14 , 14 in the traveling system 60 are driven by the power output by the engine 11 . Specifically, the traveling system 60 includes a belt transmission mechanism 61, a hydrostatic transmission mechanism (HST, Hydraulic Static Transmission,) or a hydraulic continuously variable transmission mechanism 62, and left and right rear wheels 14, 14. The hydraulic continuously variable transmission mechanism 62 is connected to the lower end of the rear of the machine body 12 for transmitting the output power of the engine 11 to the left and right rear wheels 14 , 14 . Thus, the output power of the engine 11 can be transmitted to the left and right rear wheels 14 , 14 through the belt transmission mechanism 61 and the hydraulic continuously variable transmission mechanism 62 .

The hydraulic continuously variable transmission mechanism 62 can convert the rotation direction of the input shaft 62a driven by the engine 11 into the forward or backward rotation of the output shaft 62b to drive the left and right rear wheels 14, 14 Rotate in forward or backward direction. In addition, the hydraulic continuously variable transmission mechanism 62 can continuously change the rotational speed transmission ratio between the input shaft 62a and the output shaft 62b. In other words, the hydraulic continuously variable transmission mechanism 62 can provide one of three modes according to the position of the swingable shift lever 63 connected to the transmission control shaft 62c. The three modes of the hydraulic continuously variable transmission mechanism 62 include a neutral mode, in which the gear lever 63 is located in the neutral position Tn (stop position), and the output shaft 62b stops rotating; In this mode, the output shaft 62b can rotate forward with a continuously variable speed; and in a reverse rotation transmission mode, in this mode, the output shaft 62b can rotate backward with a continuously variable speed. According to the position of the gear lever 63, the transmission control shaft 62c can be dedicated to controlling the hydraulic continuously variable transmission mechanism 62 to switch among the above three modes.

When the gear lever 63 is in the neutral position Tn, the output shaft 62b stops rotating. When the gear lever 63 swings out from the neutral position Tn in a certain direction, the hydraulic continuously variable transmission mechanism 62 is switched to the forward rotation transmission mode, so as to switch from the neutral position in a certain direction according to the gear lever 63 The output shaft 62b is rotated forward when the swing angle of the bit Tn is continuously variable to the output shaft 62b. When the gear lever 63 hangs out from the neutral position Tn in the reverse direction of a certain direction, the hydraulic continuously variable transmission mechanism 62 is switched to the reverse rotation transmission mode to When the output shaft 62b is continuously shifted by the angle swinging from the neutral position Tn in the reverse direction, the output shaft 62b is rotated backward.

The hydraulic continuously variable transmission mechanism 62 can be manipulated by the transmission control mechanism 70 to change the traveling speed of the working machine 10 . As shown in FIGS. 2 and 7 , the transmission control mechanism 70 mainly includes a joystick 71 , a support 72 , a swing arm 73 and a pull rod 74 .

The hydraulic continuously variable transmission mechanism 62 is manipulated by swinging the joystick 71 to change the traveling speed of the working machine 10 . As shown in FIG. 1 , the hydraulic continuously variable transmission mechanism 62 can be arranged on one side of the work machine 10 for manual operation by an operator sitting on the seat 15 . The joystick 71 can swing in the longitudinal direction of the machine body 12 .

7 and 8 show the joystick 71 positioned at the neutral position Mn (stop position). The joystick 71 in the neutral position Mn keeps the hydraulic continuously variable transmission mechanism 62 in the neutral mode or the stop mode in which the working machine 10 stops running. The joystick 71 can be swung forward and backward from the neutral position Mn to manipulate the hydraulic continuously variable transmission mechanism 62 to move the working machine 10 forward or backward, and to change the traveling speed of the working machine 10 . That is, when the control lever 71 swings forward from the neutral position Mn, the hydraulic continuously variable transmission mechanism 62 is manipulated to drive the working machine 10 forward. The joystick 71 is oscillating within a forward travel area Fm constituted by the neutral position Mn and the forward travel position Mf. When the joystick 71 is at the forward position Mf, the working machine 10 is traveling forward at the highest traveling speed. As the control lever 71 gradually approaches the forward travel position Mf, the hydraulic continuously variable transmission mechanism 62 is manipulated to increase the forward travel speed of the working machine 10 .

When the control lever 71 swings backward from the neutral position Mn, the hydraulic continuously variable transmission mechanism 62 is manipulated to control the working machine 10 to move backward. The joystick 71 is oscillating within a backward travel region Rm constituted by the neutral position Mn and the backward travel position Mr. When the joystick 71 is at the backward traveling position Mr, the working machine 10 travels backward at the highest traveling speed. As the control lever 71 gradually approaches the backward traveling position Mr, the hydraulic continuously variable transmission mechanism 62 is manipulated to increase the traveling speed of the working machine 10 traveling backward.

As shown in FIGS. 7 to 10 , the support member 72 includes a support body 72 a and a support shaft 72 b extending laterally from the support body 72 a toward the working machine 10 . The support member 72 also includes a planar support plate 72c extending downward from the side of the support body 72a. The joystick 71 includes a base 71a connected to the supporting body 72a. The joystick 71 extends upward from the supporting body 72 a and is prohibited from swinging relative to the supporting body 72 a in the longitudinal direction of the machine body 12 . In other words, the support 72 is provided on the base 71 a of the joystick 71 . The support member 72 can swing in a certain direction (longitudinal direction of the machine body 12 ) together with the operating rod 71 so as to operate the hydraulic continuously variable transmission mechanism 62 . The support shaft 72b is supported by a bearing 75 connected to the machine body 12 and can rotate relative to the bearing 75 . The planar support plate 72c has a side surface facing laterally toward the working machine 10 . The side surface of the planar support plate 72c includes a vertically extending guide groove 72d formed at a front lower portion thereof.

The swing arm 73 is an elongated plate extending in the longitudinal direction of the working machine 10 . The swing arm 73 has a longitudinal middle portion connected to the lower rear portion of the planar support plate 72c by a support pin 76, whereby the swing arm 73 can swing vertically. That is, the longitudinal middle portion of the swing arm 73 is supported by the support member 72 so that the swing arm 73 can swing in the same direction as the support member 72 swings. The swing arm 73 has a front portion that slopes downward.

Connected to the front end of the swing arm 73 is a guide pin 77 extending laterally along the working machine 10 . As shown in FIG. 8 , the guide pin 77 is located in front of a second line L2 passing through the center point P1 of the support shaft 72 b and the center point P2 of the support pin 76 . The center point P1 constitutes the center point of pivoting of the support 72 . The center point P2 constitutes the center point at which the swing arm 73 swings. The guide pin 77 is installed in the guide groove 72d. When the swing arm 73 vertically swings on the support pin 76, the guide pin 99 is guided by the guide groove 72d.

As shown in FIGS. 7 to 10 , the outer sleeve 52 has an opposite end portion 52c (opposite end portion) connected to the support member 72 . The swing arm 73 has a rear end connected to the opposite end 53 b of the inner cable 53 via a cable connection pin 78 . The steel cable 51 can transmit the turning angle of the steering wheel 31 to the swing arm 73, and this process will be described in detail below.

As shown in FIG. 8 , the cable connection pin 78 is located behind the second line L2 and deviates downward from a third line L3 passing through the center point P2 and the center point P3 of the guide pin 77 . The support pin 76 , the guide pin 77 and the cable connection pin 78 are parallel to the support shaft 72 b of the support member 72 .

As shown in FIG. 7 to FIG. 10 , the pull rod 74 is connected with the swing arm 73 to transmit the force for manipulating the joystick 71 to the transmission control shaft 62 c of the hydraulic continuously variable transmission mechanism 62 . Specifically, the pull rod 74 has an end portion 74 a connected to the guide pin 77 .

As shown in FIG. 9 , the transmission control mechanism 70 is covered by a cover 16 covering the top of the machine body 12 . That is to say, the transmission control mechanism 70 is disposed in a downwardly open space formed by the side of the machine body 12 . The arrangement of placing the transmission control mechanism 70 in the downwardly open space formed by the side of the machine body 12 can make the working machine 10 very easy for the installation of other components other than the transmission control mechanism 70 Provide space. As a result, the degree of freedom in mounting other components than the transmission control mechanism 70 is improved.

As shown in Figure 7, the pull rod 74 extends backward from the guide pin 77, and it has a rear end 74b, and the rear end 74b passes through a swingable first intermediate arm 81, an intermediate operating shaft 82, a swingable The second intermediate arm 83 and the hinge 84 are connected to the gear lever 63 of the hydraulic continuously variable transmission mechanism 62 . The intermediate steering shaft 82 and the transmission control shaft 62c of the hydraulic continuously variable transmission mechanism 62 are parallel to the guide pin 77 and extend laterally toward the working machine 10 . The first middle arm 81 extends forward from the middle steering shaft 82 .

The intermediate steering shaft 82 is located in front of the hydraulic continuously variable transmission mechanism 62 , is supported by the machine body 12 and is rotatable. The first intermediate arm 81 has a proximal end connected to one end of the intermediate operating shaft 82 , and a distal end 81 a connected to the rear end 74 b of the pull rod 74 . The second intermediate arm 83 has a proximal end connected to the other end of the intermediate steering shaft 82 and a distal end connected to one end of the hinge 84 . The other end of the hinge 84 is connected to the gear lever 63 .

As shown in FIGS. 7 to 10 , the supporting body 72 a includes an upper front portion carrying an upper spring engaging member 86 . The front end of the swing arm 73 is connected to the lower spring engaging member 87 by means of the guide pin 77 . The return spring 57 extends between the upper and lower spring joints 86 , 87 and engages with the upper and lower spring joints 86 , 87 . The return spring 57 (which extends between the front upper part of the support body 72a and the front end of the swing arm 73, and is engaged with the front upper part of the support body 72a and the front end of the swing arm 73) is Push the front end of the swing arm 73 in a certain direction (counterclockwise in FIG. 8 ), so that the front end of the swing arm 73 is always lifted or moved upward relative to the supporting member 72 . In other words, the return spring 57 pushes the swing arm in a direction capable of returning the transmission control shaft 62c ( FIG. 2 ) of the hydraulic continuously variable transmission mechanism 62 to a position that reduces the travel speed of the working machine 10 73.

The front end of the swing arm 73 is pushed by the return spring 57 so as to pull the inner cable 53 of the steel cable 51 all the time. As a result, the inner cable 53 always pulls the slide pin 41 along the guide portion 43 a in the direction of the intermediate shaft 35 ( FIGS. 3 and 5 ).

When the steering angle is 0 (or the steering wheel 31 is in the straight state), that is, when the working machine 10 is running straight, the intermediate shaft 35, the sliding pin 41 and the connecting pin 42 are all located at the first On the line L1. The sliding pin 41 is maintained at a linear movement position Ps away from the intermediate shaft 35 .

The swing arm 73 is always urged by the return spring 57 in the direction of returning the transmission control shaft 62c to the position where the traveling speed of the working machine 10 is reduced. That is to say, the swing arm 73 is always pushed by the return spring 57 in a direction capable of providing a failsafe function. Therefore, even if an accident occurs in the steering angle transmission mechanism 39, for example, the inner cable 53 is broken, the swing arm 73 will be pushed by the return spring 57 to adjust the transmission control shaft 62c. Swing in the direction of returning to the position of reducing the traveling speed of the working machine 10 , and adjust the transmission control shaft 62 c back to the position of reducing the traveling speed of the working machine 10 . The steering angle transmission mechanism 39 thus provides an improved failsafe function.

According to the relative angle between the pull rod 74 and the swing arm 73 or the relative angle between the pull rod 74 and the first intermediate arm 81, the pushing force of the return spring 57 is set to ensure that the transmission control shaft 62c can be adjusted back to the lowered position. The position of the travel speed of the working machine 10 is described.

The support member 72, the swing arm 73, the pull rod 74 and the steering angle transmission mechanism 39 jointly constitute a reset mechanism 90 arranged on the base 71a, so that when the hydraulic continuously variable transmission mechanism 62 is manipulated by the joystick 71 and the steering wheel 31 is turned, that is, When the working machine 10 is steered, the hydraulic continuously variable transmission mechanism 62 is returned to the position where the traveling speed of the working machine 10 is reduced.

When the hydraulic continuously variable transmission mechanism 62 is manipulated by the joystick 71 , the working mode of the hydraulic continuously variable transmission mechanism 62 is as follows.

As shown in FIG. 8 , when the control lever 71 swings from the neutral position Mn to the forward direction Fr or enters the forward travel range Fm, the support member 72 and the swing arm 73 swing clockwise together with the control lever 71 at the central point P1. FIG. 11 shows that the swing arm 73 has swung to the forward travel position Mf.

The clockwise swing of the swing arm 73 moves the pull rod 74 backward, thereby making the first intermediate arm 81 swing clockwise. Clockwise swinging of the first intermediate arm 81 rotates the intermediate steering shaft 82 clockwise, thereby causing the second intermediate arm 83 and hinge 84 ( FIG. 7 ) to swing the gearshift lever 63 clockwise. Then, the hydraulic continuously variable transmission mechanism 62 shifts from the neutral mode in which the output shaft 62b stops rotating to the forward rotation transmission mode in which the output shaft 62b rotates forward, thereby driving the working machine 10 forward, wherein the The increase in the rotational speed of the output shaft 62b depends on the angle by which the joystick 71 is swung forward from the neutral position Mn.

As shown in FIG. 8 , when the joystick 71 swings from the neutral position Mn to the rear Rr or enters the backward travel zone Rm, the hydraulic continuously variable transmission mechanism 62 shifts from the neutral mode to the output shaft 62b backward Rotational reverse rotation transmission mode, so that the working machine 10 travels backward, wherein, the increase of the rotation speed of the output shaft 62b depends on the backward swing angle of the joystick 71 from the neutral position Mn.

When turning the steering wheel 31 ( FIG. 2 ), the hydraulic continuously variable transmission mechanism 62 works as follows.

As shown in FIG. 8 , when the joystick 71 is in the neutral position Mn, the working machine 10 ( FIG. 2 ) stops running. As shown in FIG. 5 , the intermediate shaft 35 , the sliding pin 41 and the connecting pin 42 are all on the first line L1 . The sliding pin 41 is on the linear motion position Ps.

When the steering wheel 31 is turned leftward or rightward with the control lever 71 in the neutral position Mn, the swing of the first arm 44 and the second arm 45 ( FIG. 6 ) depends on the degree of rotation of the steering wheel 31 angle. The swinging of the first and second arms 44, 45 causes the slide pin 41 to slide toward the intermediate shaft 35 because the slide pin 41 is guided by the guide portion 43a. The sliding amount or sliding distance of the sliding pin 41 corresponds to the rotation angle. Therefore, the steering angle conversion mechanism 40 can convert the steering angle into a linear sliding or displacement amount of the slide pin 41 .

The sliding of the sliding pin 41 towards the intermediate shaft 35 loosens the inner cable 53 ( FIG. 3 ), thereby allowing the swing arm 73 to move from the solid line in FIG. 12 under the pushing force of the return spring 57 ( FIG. 8 ). The position of the dotted line in Fig. 12 swings counterclockwise. During the counterclockwise swing of the swing arm 73, the center point P3 of the guide pin 77 moves to the position P3a by moving along an arcuate path Los (small arc path Los) having the center point P2. Movement of the center point P3 of the guide pin 77 towards the position P3a moves the tie rod 74 counterclockwise to the position marked (in FIG. 12 ) by the dotted line.

Afterwards, the end 74a (Fig. 8, Fig. 10) of the tie rod 74 connected to the guide pin 77 is moved to the position P3a by moving along the arc-shaped route Lom (large-arc-shaped route Lom) having the center point P4, said center point P4 is a connection point between the tie rod 74 and the first intermediate arm 81 . The large arc route Lom basically coincides with the small arc route Los. That is, even when the center point P3 of the guide pin 77 shifts position according to the steering angle, the small arc line Los and the large arc line Lom are separated from each other with substantially no gap. In other words, the tie rod 74 does not move in its longitudinal direction. Therefore, the position of the center point P4 remains substantially unchanged (ie, no changes affecting the hydraulic continuously variable transmission mechanism 62 occur). As a result, the output shaft 62a of the hydraulic continuously variable transmission mechanism 62 remains in an idle state where it does not rotate. Therefore, the working machine 10 remains in an idle state in which the running is stopped.

The positions of the center points P1, P2, P3, P4 and the position of the center point P5 of the intermediate steering shaft 82 are set so that the first intermediate arm 81 does not move even when the center point P3 of the guide pin 77 moves to the position P3a. It will swing when the joystick 71 is in the neutral position Mn. Therefore, regardless of the steering angle, even when the engine 11 ( FIG. 2 ) is running, the working machine 10 can maintain a stationary state when the control lever 71 is in the neutral position.

When the joystick 71 swings from the neutral position Mn through the forward travel area Fm to such as the forward travel position Mf, the first intermediate arm 81 is tilted from the front down (marked by the dotted line in FIG. 13 ) Swing to the vertical position (marked by the short solid line in FIG. 13 ) allows the work machine 10 ( FIG. 2 ) to travel forward at maximum travel speed. When the steering wheel 31 ( FIG. 2 ) turns left or right through a certain steering angle, the inner cable 53 is loosened according to the steering angle, so that the swing arm 73 is under the action of the driving force of the return spring 57 ( FIG. 11 ). Next, swing counterclockwise from the position marked by the long solid line in Figure 13 to the position marked by the long dashed line in Figure 13. During the counterclockwise swing of the swing arm 73, the center point P3 of the guide pin 77 moves to the position P3a along a small arc-shaped route with the center point P2. That is, the guide pin 77 has moved forward by a greater amount or distance δ.

The movement of the center point P3 of the guide pin 77 to the position P3a causes the pull rod 74 to move counterclockwise from the position marked by the long solid line to the position marked by the long dashed line. Then, since the guide pin 77 has moved by a relatively large amount δ, the tie rod has moved a large distance forward. Thus, the center point P4 moves forward to the position P4a to make the first intermediate arm 81 swing back or swing counterclockwise from the vertical position marked by the short solid line to the inclined position where the working machine 10 remains stationary. Finally, the intermediate arm 81 reaches the deceleration position marked by the dotted line. In this deceleration position, the shift lever 63 swings in a certain direction to control the hydraulic continuously variable transmission mechanism 62 ( FIG. 7 ) to reduce the traveling speed of the working machine 10 .

As can be seen from the above, by turning the steering wheel 31 to drive the reset mechanism 90, the hydraulic continuously variable transmission mechanism 62 manipulated by the joystick 71 returns to the output shaft 62b of the hydraulic continuously variable transmission mechanism 62 The position where the speed is reduced. As a result, the travel speed of the working machine 10 is also automatically reduced.

It should be noted that the support shaft 72b shown in FIG. 7 is rotatable relative to the bearing 75 in the presence of a predetermined amount of friction therebetween. This frictional force keeps the position of the joystick 71 unchanged even when the operator's hand is off the joystick 71 . For example, the friction force is set such that the position of the joystick 71 remains constant independent of the steering force turning the steering wheel 31 ( FIG. 2 ). Because the control lever 71 and the supporting member 72 are not affected by the steering force, the steering wheel 31 can be rotated to drive the reset mechanism 90, so that the hydraulic continuously variable transmission mechanism 62 returns to reduce the driving speed of the working machine 10. Under the premise of the position, the steering force can be set to be small.

Next, the description above is summarized.

In a preferred embodiment of the present invention, as shown in FIG. 2 , a reset mechanism 90 capable of automatically reducing the travel speed of the working machine 10 when the working machine 10 turns is installed on the base 71 a of the joystick 71 . Since the reset mechanism 90 is installed on the base portion 71a, the structure of the reset mechanism 90 is simpler than the structure in which the reset mechanism 90 is installed separately from the joystick 71 . Furthermore, since the reset mechanism 90 is installed on the base portion 71 a of the joystick 71 , the working machine 10 can also provide sufficient installation space for other components except the reset mechanism 90 . As a result, the degree of freedom in the installation of other components is greatly improved.

The reset mechanism 90 is very useful for a ride-on work machine in which the working system 20 ( FIG. 1 ) and the traveling system 60 are driven by a single engine 11 . This is because the reset mechanism 90 can not only reduce the speed of the engine 11, but also reduce the running speed of the working machine 10 when the working machine 10 turns, so that the running speed of the working system 20 can be maintained when the working machine 10 decelerates and turns. .

In this embodiment, the reset mechanism 90 has a simple structure, which includes a support member 72 that can swing in a certain direction together with the joystick 71 to manipulate the hydraulic continuously variable transmission mechanism 62 to change the driving speed of the working machine 10 , a swingable swing arm 73 supported by the support member 72 , a pull rod 74 connected to the swing arm 73 , and a steering angle transmission mechanism 39 for transmitting the turning angle of the steering wheel 31 to the swing arm 73 .

When the steering wheel is at a position where the working machine 10 can travel straight, the steering angle is zero. In this case, since the operating lever 71 swings together with the support 72 , the swing arm 73 swings together with the operating lever 71 and the support 72 . The swing of the swing arm 73 manipulates the transmission control shaft 62c of the hydraulic continuously variable transmission mechanism 62 through the pull rod, thereby changing the traveling speed of the working machine 10 . When the steering wheel 31 is turned during the operation of the hydraulic continuously variable transmission mechanism 62 , the turning angle of the steering wheel 31 is transmitted to the swing arm 73 through the steering angle transmission mechanism 39 . Afterwards, the swing arm 73 swings relative to the support member 72 according to the steering angle, so as to operate the transmission control shaft 62c of the hydraulic continuously variable transmission mechanism 62 by means of the pull rod 74 to lower the travel of the working machine 10 speed.

In the present embodiment, the steering angle transmission mechanism that transmits the steering angle to the swing arm 73 includes the wire cable 51 . The beneficial effect of this is that the positioning of the swing arm 73 relative to the steering wheel 31 is not restricted. Thus, the degree of freedom in mounting the return mechanism 90 is improved.

It should be noted that the steering angle transmission mechanism 39 does not necessarily include the steering angle conversion mechanism 40 . If the steel cable 51 and the return spring 57 are designed to transmit the steering angle, the steel cable 51 and the return spring 57 are sufficient to complete the transmission of the steering angle to the swing arm 73 . For example, the cable 51 is arranged to transmit the steering angle change to the swing arm 73 without converting the steering angle change into a linear displacement.

Although the above-mentioned transmission control mechanism 70 has the first intermediate arm 81, the intermediate operating shaft 82, the second intermediate arm 83 and the hinge 84, these parts (the first intermediate arm 81, the intermediate operating shaft 82, the second intermediate arm 83 and the hinge 84) It is not necessary for the working machine 10. One or more of these components may be appropriately used in consideration of the overall layout design of the work machine 10 . For example, the rear end 74b of the pull rod 74 of the transmission control mechanism 70 is directly connected to the gear lever 63. In this case, the gear lever 63 and the first intermediate arm 81 have the same length and can be arranged in the same direction superior.

The ride-on work machine 10 provided by the present invention is preferably a ride-on lawnmower.

Claims (2)

1. a riding type working rig (10), comprising:

Bearing circle (31);

Engine (11);

Drive wheel (14,14);

Hydraulic stepless speed change transmission device (62), for by the transmission of power of engine (11) to drive wheel (14,14);

Swingable joystick (71), for handling described hydraulic stepless speed change transmission device (62) to change described working rig (10) moving velocity, described joystick (71) comprises base portion (71a);

Bringing-back mechanism (90), for to be handled by joystick (71) described hydraulic stepless speed change transmission device (62) and steering wheel rotation (31) time, described hydraulic stepless speed change transmission device (62) is back to and reduces the position of described working rig (10) moving velocity;

Wherein, described Bringing-back mechanism (90) is arranged on the base portion (71a) of described joystick (71);

Described hydraulic stepless speed change transmission device (62) comprises transmission actuating spindle (62c);

Described Bringing-back mechanism (90) comprising:

Supporting member (72), is connected with the base portion (71a) of described joystick (71), and swings the moving velocity changing described working rig (10) in a certain direction together with described joystick (71);

Swing arm (73), is supported by described supporting member (72), and swings on the direction identical with the direction that described supporting member (72) swings;

Pull bar (74), is connected with described swing arm (73), for the power handling described joystick (71) being passed to the transmission actuating spindle (62c) of described hydraulic stepless speed change transmission device (62); And

Steering angle transmission mechanism (39), the steering angle for being turned over by described bearing circle (31) passes to described swing arm (73), swings according to described steering angle to make described swing arm (73).

2. working rig according to claim 1, is characterized in that, described steering angle transmission mechanism (39) comprising:

Wirerope (51), for transmitting described steering angle to described swing arm (73); And

Retracing spring (57), for promoting described swing arm (73) in a certain direction, the transmission actuating spindle (62c) of described hydraulic stepless speed change transmission device (62) to be recalled to the position to reducing working rig (10) moving velocity.