JP2011178241A - Brake structure of work vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake structure of a work vehicle which can make vehicle body compact by effectively utilizing a lower space of the brake pedal while increasing a degree of freedom of mounting the brake structure on the work vehicle. <P>SOLUTION: A base end side part 20b of a brake pedal 20, which has a step part 20e at one side and a pivotally supporting part 20a at the other side, is provided at a position 37 at the floor side making its longitudinal direction follow the horizontal direction. A pedal effort transmission member 61 is arranged between the tip end of the based end side part 20b of the brake pedal 20 and a brake device 19 provided below the brake pedal 20. A pedal effort direction changing mechanism 62, which changes the operation direction of the pedal effort transmission member 61, is provided at the side opposite to the pivotally supporting part 20a against the position of the step part 20e. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a brake structure for a work vehicle in which a long brake pedal having a foot part on one side and a pivotal part on the other side is provided with its longitudinal direction along the horizontal direction.

  Conventionally, in this type of work vehicle brake structure, a rod is interposed between an output arm that is integrally rotatable from a pivot portion of a brake pedal and an input arm of a brake device provided below the brake pedal. Some have been worn (see, for example, Patent Document 1).

JP 2006-115740 A

  In the brake structure of the conventional work vehicle, the rod that connects the brake pedal and the brake device is located in the space below the brake pedal. For this reason, for example, when the transmission case is provided in the space below the brake pedal, the transmission case is arranged to prevent the rod from interfering with the transmission case when the transmission case is provided with a brake device. If the position is restricted or the transmission case and brake device are configured separately, the brake device is placed in a restricted position to prevent the rod from interfering with the transmission case. The degree of freedom of mounting the device on a work vehicle was narrowed. Further, since it is necessary to dispose the transmission case while dodging the rod, the space below the brake pedal cannot be used effectively, for example, a dead space occurs in the space below the brake pedal.

  An object of the present invention is to provide a brake structure for a work vehicle that can make the airframe compact by effectively using the space below the brake pedal while increasing the degree of freedom of mounting the brake device on the work vehicle. In the point.

  A first characteristic configuration of a brake structure for a work vehicle according to the present invention is that a base portion of a brake pedal having a stepped portion on one side and a pivotal portion on the other side is placed on the floor while keeping its longitudinal direction along the horizontal direction. A pedal force transmission member is provided between the distal end portion of the base end side portion of the brake pedal and a brake device provided below the brake pedal, and the operating direction of the pedal force transmission member is changed. The pedal force direction changing mechanism to be changed is provided on the side opposite to the pivot portion with respect to the position of the stepping portion.

  The pedal force transmitting member is disposed between the distal end portion of the base end portion of the brake pedal and the brake device, and the pedal force direction changing mechanism is provided on the side opposite to the pivot portion with respect to the position of the foot pedal portion. Thereby, a brake device can be arrange | positioned in the state which open | released the downward space of the brake pedal. For this reason, for example, when the transmission case is disposed in the space below the brake pedal, if the transmission case is equipped with a brake device, the position of the transmission case is not restricted, or the transmission case and the braking device Is configured separately, the degree of freedom of mounting the brake device on the work vehicle is increased, for example, the arrangement position of the brake device is not restricted.

  Usually, since the longitudinal direction of the base end side portion of the brake pedal faces the front of the body, the brake device is disposed in front of the body with the space below the brake pedal open. Therefore, the brake device can be easily adjusted from the front of the machine body, and maintenance is improved. In addition, since the dead space does not occur in the space below the brake pedal, the space below the brake pedal can be effectively used to make the airframe compact.

  The second characteristic configuration of the present invention is that the pedal force transmission member is a cable, and the pedal force direction changing mechanism is a pulley provided on the floor side.

  By using a flexible cable as the treading force transmission member, it is easier to select a routing route than a rod or the like, and the aircraft can be made more compact. In addition, by using a pulley provided on the floor side as the pedaling force direction changing mechanism, the operation direction of the pedaling force transmission member can be changed with a simple configuration in which a cable is wound around the pulley.

  A third characteristic configuration of the present invention is that a holding member that engages with the depressed brake pedal and maintains the brake pedal in a depressed state is provided on a support shaft of the pulley so as to be swingable.

  The brake structure can be simplified by using the support shaft of the pulley also as the swing shaft of the holding member.

  According to a fourth characteristic configuration of the present invention, the cable is routed from the brake pedal to the pulley as a first direction, and the cable from the pulley to the brake device is as a second direction. The brake pedal, the pulley, and the brake device are arranged so that an angle formed between the first direction and the second direction across the pulley decreases according to depression of the brake pedal. In the point.

  In the initial stage of depression of the brake pedal, the angle formed by the first direction and the second direction is large. At this time, although the angle in the first direction changes relatively greatly with the depression of the brake pedal, the cable pull-in amount does not change so much. For this reason, the ratio that the brake pedal depression amount contributes to the actual cable pull-in amount is small. However, if the initial stage of depression of the brake pedal is exceeded, the first direction and the second direction approach in opposite directions. For this reason, the amount of depression of the brake pedal is close to that of the cable as it is.

  Therefore, with this configuration, the effect of the brake operation appears gently at the initial step of depression, and the effect increases according to the depression. For this reason, the brake structure excellent in the depression feeling can be obtained.

  According to a fifth feature of the present invention, a tension spring is provided in the middle of the cable, a contact portion for changing a direction in which the cable extends from the pulley is provided on the body portion of the brake pedal, and the body portion is provided. The plate-like member is provided with a cable tension adjusting mechanism having a plurality of engagement holes that can engage the end portion of the cable and have different distances from the contact portion.

  Usually, the initial position of the brake pedal is always constant. Therefore, if the cable extending from the pulley is in contact with the body portion of the brake pedal, the direction of the cable extending from the pulley to the brake pedal is always constant. In this state, only the initial cable tension is changed by replacing the end of the cable with another engagement hole. That is, when the tension of the cable is changed, the initial load at which the brake pedal is depressed slightly changes, but the ratio of increasing the weight according to the depression is generally maintained. Therefore, with this configuration, the tension of the cable can be changed without greatly changing the feeling of depression of the brake pedal.

  Even if the cable length itself has an error in the initial stage of brake installation, the cable tension can be set satisfactorily by changing the end of the cable to another engagement hole. Even if the cable is extended due to long-term use, the cable tension can be improved over a long period of time by replacing the end of the cable with another engagement hole having a long distance from the contact part. Can be maintained.

It is a side view which shows a combine. It is the schematic which shows a transmission structure. It is a longitudinal cross-sectional view which shows the brake structure when a parking brake is an off state. It is a longitudinal cross-sectional view which shows the brake structure when a parking brake is an ON state. It is a front view which shows a brake structure. It is a longitudinal cross-sectional view which shows the brake structure when a parking brake is an off state. It is a longitudinal cross-sectional view which shows the brake structure in the state by which engagement with the notch part of a 1st bending part and the intermediate part of a brake pedal was cancelled | released. It is a VIII-VIII arrow directional cross-sectional view of FIG.

  Hereinafter, the structure which applied the brake structure which concerns on this invention to the normal type combine as an example of a working vehicle is demonstrated.

(overall structure)
As shown in FIG. 1, the combine includes a crawler traveling device 1, a body frame 2 provided on an upper portion of the crawler traveling device 1, a cutting unit 3 provided at a front portion of the body frame 2, and the like. The machine body frame 2 includes a driving unit 4 operated by an operator, a threshing device 5 for threshing and sorting the harvested cereal, a lifting screw conveyor 6 for lifting the grains discharged from the threshing device 5, and its lifting A grain tank 7 for storing the grains supplied from the screw conveyor 6 and a discharge auger 8 for discharging the grains from the grain tank 7 to the outside are equipped.

(Transmission structure)
FIG. 2 shows a transmission structure in which the power of the engine 11 is transmitted to the crawler traveling device 1, the cutting unit 3, and the threshing device 5.

  Specifically, the power of the output shaft 11a of the engine 11 is transmitted to the threshing drive shaft 5a of the threshing device 5 via the belt-type transmission mechanism 12, and the threshing feed chain (illustrated) in the threshing device 5 from this threshing drive shaft 5a. Not) and a handling cylinder (not shown).

  The power of the output shaft 11 a of the engine 11 is transmitted to the input shaft 14 a of the hydrostatic continuously variable transmission 14 provided in the transmission case 15 via the belt transmission mechanism 13, and the hydrostatic continuously variable transmission 14. The power of the output shaft (not shown) is transmitted to the pretreatment drive shaft 3a of the cutting unit 3 through the intermediate shaft 16 and the belt-type transmission mechanism 17, and the pulling device (in the cutting unit 3) from the pretreatment drive shaft 3a. (Not shown) and a reaping device (not shown).

  The power of the intermediate shaft 16 is transmitted to the left and right output shafts 18 positioned below the transmission case 15 via a gear transmission mechanism (not shown), and the power of the left output shaft 18L is transmitted to the left crawler travel device. In 1L, the power of the right output shaft 18R is transmitted to the right crawler traveling device 1R.

  The mission case 15 is provided with a parking brake 19 (an example of a brake device). When the brake pedal 20 is depressed, the operation arm 19a of the parking brake 19 is operated via the pedal force transmission mechanism TK provided between the brake pedal 20 and the parking brake 19, and the left and right crawler travel devices 1L and 1R are operated. It is configured to apply a brake. The pedal force transmission mechanism TK will be described in detail later.

(Operation part)
As shown in FIGS. 1, 3 to 7, the driving unit 4 is installed in front of the fuselage, and includes a floor 31, a driving seat 32 installed above the floor 31, and driving. A front control tower 33 mounted on the upper surface of the floor portion 31 in a state positioned in front of the seat 32 and a side control mounted on the upper surface of the floor portion 31 in a state positioned on the left side of the driver seat 32. And a tower 34. The brake pedal 20 and the brake operation lever 35 are provided between the driver seat 32 and the front control tower 33 so as to protrude upward from the floor 31. The brake pedal 20 and the brake operation lever 35 are disposed in a portion of the floor 31 close to the side control tower 34 so as to be adjacent to a wall portion outside the fuselage of the side control tower 34, and the pedal force transmission mechanism TK. Etc., and is linked to the parking brake 19 in a straight line in the vertical direction when viewed from the front.

  A front vertical frame 36 and a rear vertical frame 37 are erected on the body frame 2. A front-rear frame 38 is connected between the upper portions of the front and rear vertical frames 36, 37. The floor portion 31 is supported by the front vertical frame 36, the rear vertical frame 37, and the front and rear frame 38, and a lower space for accommodating the transmission case 15 and the like is formed below the floor portion 31.

(break pedal)
As shown in FIGS. 3 to 7, the brake pedal 20 includes a lateral shaft portion 20 a (pivotal support portion) that is rotatably attached to an upper portion of a rear vertical frame 37 (an example of a portion on the floor side). An example), a proximal end portion 20b extending forward from the shaft portion 20a, an intermediate portion 20c extending laterally from a distal end portion of the proximal end portion 20b (an example of a body portion), and a distal end of the intermediate portion 20c A tip end portion 20d extending upward from the portion and a stepping portion 20e fixed to the tip end portion of the tip end portion 20d are configured to be swingable in the vertical direction around the shaft portion 20a.

  A front end side portion 20d and a stepping portion 20e of the brake pedal 20 protrude upward from the floor portion 31. An abutting piece 20f is fixed to the front end portion 20d of the brake pedal 20. The contact piece 20f is configured to be able to prevent the brake pedal 20 from swinging upward from a predetermined position by contacting the front-rear frame 38.

(Brake operation lever)
As shown in FIGS. 3 to 7, a lateral support shaft 39 is fixed in a cantilevered manner to the upper part of the front vertical frame 36. The brake operation lever 35 includes an upward lever portion 35a that is rotatably attached to the support shaft 39, and a grip portion 35b provided at the tip of the lever portion 35a. It is configured to be swingable in the direction.

  A lever portion 35 a and a grip portion 35 c of the brake operation lever 35 protrude upward from the floor portion 31. An arm 40 (an example of a holding member) is fixed to the lever portion 35 a of the brake operation lever 35. The arm 40 includes a flat plate portion 40a, a first bent portion 40b extending rearward and downward from one end portion of the flat plate portion 40a, and a second bent portion 40c extending rearward from the other end portion of the flat plate portion 40a. Yes. The lever portion 35a of the brake operation lever 35 is fixed to the first bent portion 40b. On the lower side (front end side) of the first bent portion 40b, a notch portion 40d that can engage with the intermediate portion 20c of the brake pedal 20 is formed. An attachment member 41 is fixed to the second bent portion 40c. A pin 42 protruding forward while passing through a substantially L-shaped notch 41 a formed in the mounting member 41 is fixed to the upper part of the front vertical frame 36. A plate-shaped ring member 43 is attached to the tip of the pin 42. A compression spring 44 is interposed between the ring member 43 and the attachment member 41.

(Operation to keep the brake pedal depressed)
As shown in FIGS. 3 and 6, the mounting member 41 and the arm 40 are urged rearward by the compression spring 44, and the brake operation lever 35 maintains the standing position (engagement position) P1. When the brake pedal 20 is depressed in this state, the notch 40d of the arm 40 is engaged with the intermediate portion 20c of the brake pedal 20 as shown in FIG. 4, and the brake pedal 20 maintains the depressed state. In order to release the depression of the brake pedal 20, the brake operation lever 35 is operated rearward against the compression spring 44. Thereby, as shown in FIG. 7, the engagement between the cutout portion 40d of the first bent portion 40b and the intermediate portion 20c of the brake pedal 20 is released, and the brake pedal 20 returns to the original state. In this way, when the brake pedal 20 is depressed by a predetermined amount, the depressed state of the brake pedal 20 is maintained.

(Mission case)
As shown in FIGS. 3 to 5, the transmission case 15 includes a hydrostatic continuously variable transmission 14 at the top and a parking brake 19 (an example of a brake device) on the lateral side of the bottom. . An operation arm 19 a is fixed to the input shaft 19 b of the parking brake 19. A return spring 45 is interposed between the pin 19c erected on the parking brake 19 and the operation arm 19a so as to be positioned outside the input shaft 19b of the parking brake 19. A long first metal fitting 46 is attached to the tip of the operation arm 19a. A pin 47 is attached to the distal end portion of the operation arm 19a, and an elongated guide hole 46a into which the pin 47 is inserted is formed at the proximal end portion of the first metal fitting 46. A second metal fitting 48 is attached to the mission case 15. The bent portion 48a of the second metal fitting 48 is formed with a hole 48b through which the first metal fitting 46 passes. A compression spring 49 is interposed between the bent portion 48 a of the second metal fitting 48 and the step 46 b of the first metal fitting so as to be located outside the first metal fitting 46.

(Treading force transmission mechanism)
As shown in FIGS. 3 to 8, a pedaling force transmission mechanism TK is provided across the tip of the brake pedal 20 and the parking brake 19. The pedal force transmission mechanism TK includes a cable 61 (an example of a pedal force transmission member), a pulley 62 (roller) around which the cable 61 is wound (an example of a pedal force direction changing mechanism), and a fan-shaped mounting plate to which one end of the cable 61 is connected. 63 (an example of a plate-like member), and a tension spring 64 interposed between the other end of the cable 61 and the first metal fitting 46.

  Specifically, the pulley 62 is provided on the floor side opposite to the shaft portion 20a with respect to the position of the stepping portion 20e. The pulley 62 is supported by the support shaft 39 so as to be free to rotate and to be slidable along the support shaft 39 while being sandwiched between the first bent portion 40 b and the second bent portion 40 c of the arm 40. The attachment plate 63 is attached to the intermediate portion 20c of the brake pedal 20, and extends in a direction along the proximal end portion 20b. A plurality of engaging holes 63a are formed at locations on the radially outer side of the mounting plate 63 at intervals in the circumferential direction. Fixing brackets 61b each having an engagement hole 61a are fixed to both ends of the cable 61. The cable 61 is connected to the attachment plate 63 by pin-connecting the engagement hole 63a of the attachment plate 63 and the engagement hole 61a of one attachment fitting 61b fixed to one end of the cable 61. The cable 61 is connected to the tension spring 64 by hooking the hook portion 64 a of the tension spring 64 into the engagement hole 61 a of the other mounting bracket 61 b fixed to the other end of the cable 61. A slip-off preventing member 20g that prevents the cable 61 from being detached from the intermediate portion 20c of the brake pedal 20 is fixed to the intermediate portion 20c of the brake pedal 20.

  Thereby, the transmission case 15 provided with the parking brake 19 and the hydrostatic continuously variable transmission 14 can be disposed with the space below the brake pedal 20 open. The cable 61 extending forward from the mounting plate 63 attached to the intermediate portion 20c of the brake pedal 20 is changed in its extending direction upward by the contact portion 20h of the intermediate portion 20c of the brake pedal 20, and is extended by the pulley 62. The exit direction is changed downward, and the tension spring 64 is connected.

  As the engagement hole 63a to which the one mounting bracket 61b of the cable 61 is connected becomes higher, the distance between the one mounting bracket 61b and the contact portion 20h of the intermediate portion 20c of the brake pedal 20 becomes longer. Therefore, the tension of the cable 61 can be increased by replacing one mounting bracket 61b with the engaging hole 63a at the upper stage. Further, if one of the mounting brackets 61b is replaced with the lower engagement hole 63a, the tension of the cable 61 can be reduced. Therefore, a cable tension adjusting mechanism for adjusting the tension of the cable 61 is configured by replacing one of the mounting brackets 61b with the other engaging hole 63a.

  When the cable 61 and the tension spring 64 are stretched due to long-term use and the operation stroke changes to the braking state of the parking brake 19, the brake pedal 20 is maintained in the depressed state by the brake operation lever 35 as described above. It is conceivable that an appropriate braking force of the parking brake 19 cannot be obtained in the state. In this case, as described above, one of the mounting brackets 61b is replaced with the mounting plate 63 and the distance between the brake pedal 20 and the parking brake 19 (operation arm 19a) is adjusted, so that the brake pedal 20 is moved to the brake operation lever. In the state of being maintained in the depressed state by 35, an appropriate braking force of the parking brake 19 can be obtained.

(Parking brake operation when the brake pedal is depressed)
As shown in FIGS. 3 and 6, at the initial stage of depression of the brake pedal 20, the pin 19c moves downward between the lower end of the guide hole 46a of the first metal fitting 46 and the pin 19c of the operating arm 19a. There is a play part that allows The compression spring 49 provided across the first metal fitting 46 and the second metal fitting 48 is not compressed. The tension spring 64 provided across the cable 61 and the first metal fitting 46 is not pulled. Therefore, at this stage, the effect of the brake operation is not shown. Furthermore, the angle θ1 formed by the first direction a1 from the contact portion 20h of the intermediate portion 20c of the brake pedal 20 to the pulley 62 and the second direction b1 from the pulley 62 to the other end of the cable 61 is large. At this time, the angle of the first direction a1 changes relatively greatly as the brake pedal 20 is depressed, but the amount of cable 61 drawn does not change so much.

  However, as shown in FIG. 4, when the initial stage of depression of the brake pedal 20 is exceeded, the pin 19c of the operating arm 19a abuts on the lower end of the guide hole 46a of the first metal fitting 46 and further below the pin 19c. Movement to is prevented. A compression spring 49 provided between the first metal fitting 46 and the second metal fitting 48 is compressed. A tension spring 64 provided across the cable 61 and the first metal fitting 46 is pulled. Therefore, the effect of the brake operation appears at this stage. Furthermore, the angle θ2 formed by the first direction a2 and the second direction b2 approaches 0 degrees. For this reason, the depression amount of the brake pedal 20 is close to the drawing amount of the cable as it is.

  As a result, the retracted amount of the cable 61 does not change so much in the initial step of depression, so that the effect of the brake operation appears moderately. On the other hand, when the initial step of the depression of the brake pedal 20 is exceeded, the depressed amount of the brake pedal 20 remains as it is. Since the cable is close to the retracted amount, the effect of the brake operation increases according to the depression of the brake pedal 20. Therefore, it becomes a brake structure excellent in the depression feeling. The first direction a2 approaches the second direction b2, but is not parallel. As a result, a brake structure in which the effect of the brake operation gradually increases as the amount of depression of the brake pedal 20 increases.

[Another embodiment]
(1) In the above embodiment, the configuration in which the pedal force transmission member is the cable 61 is exemplified. However, the pedal force transmission member may be a link, for example.

(2) In the above-described embodiment, the configuration in which the pedal force direction changing mechanism is the pulley 62 is illustrated. However, instead of the pulley 62, for example, a seesaw mechanism may be adopted as the pedal force direction changing mechanism. In this case, a balance arm swingable around the central horizontal axis is provided, one end of the balance arm is connected to the tip of the brake pedal 20, and the other end of the balance arm is connected to the parking brake 19 by a linkage rod or the like. By doing so, a seesaw mechanism is configured. Accordingly, when one end of the balance arm is displaced downward by the depression operation of the brake pedal 20, the other of the balance arm is displaced upward, and the parking brake 19 is operated to the braking side.

(3) In the said embodiment, the structure provided with the parking brake 19 in the mission case 15 was illustrated. However, the mission case 15 and the parking brake 19 may be configured separately.

(4) Instead of the configuration in which the brake device functions as a parking brake as in the above embodiment, the brake device may function as a brake for braking during traveling. For example, the compression spring 44 provided between the tip of the pin 42 and the attachment member 41 is replaced with a tension spring. Thereby, when the brake operation lever 35 is not operated, the inclined position where the brake operation lever 35 is inclined rearward from the standing position P1 is maintained. For this reason, when the brake pedal 20 is depressed, the notch 40d of the arm 40 does not engage with the intermediate portion 20c of the brake pedal 20, so that the brake pedal 20 is not automatically held in the depressed state by the brake operation lever 35. . When the driver depresses the brake pedal 20 and manually operates the brake operation lever 35 to the front side, the notch 40d of the arm 40 is engaged with the intermediate portion 20c of the brake pedal 20, and the brake pedal 20 is maintained in the depressed state by the brake operation lever 35. In this way, the brake device can function not only as a brake for braking during traveling but also as a parking brake.

  The present invention can be applied to other work vehicles such as a self-removing combine, a carrot harvester, and a riding rice transplanter in addition to the ordinary combine.

19 Brake device (parking brake)
20 Brake pedal 20a Pivoting part 20b Base end part 20c Body part 20e Foot part 20h Contact part 37 Floor part 39 Support shaft 40 Holding member 61 Treading force transmission member, cable 62 Treading force direction changing mechanism, pulley 63 Plate-like member 63a Plural engagement holes 64 Tension springs a1, a2 First direction b1, b2 Second direction θ1, θ2 Angle

Claims (5)

A base end portion of a brake pedal having a stepping portion on one side and a pivot portion on the other side is provided in a portion on the floor portion side along the horizontal direction thereof,
A pedal force transmission member is disposed between a distal end portion of the base end side portion of the brake pedal and a brake device provided below the brake pedal;
A brake structure for a work vehicle, wherein a pedal force direction changing mechanism for changing an operation direction of the pedal force transmitting member is provided on a side opposite to the pivot part with respect to a position of the foot part.   The brake structure for a work vehicle according to claim 1, wherein the pedal force transmission member is a cable, and the pedal force direction changing mechanism is a pulley provided on a floor side.   The brake structure for a work vehicle according to claim 2, wherein a holding member that engages with the depressed brake pedal and maintains the brake pedal in a depressed state is swingably provided on a support shaft of the pulley.   The first direction sandwiching the pulley when the cable routing direction from the brake pedal to the pulley is a first direction and the cable routing direction from the pulley to the brake device is a second direction 4. The work according to claim 2, wherein the brake pedal, the pulley, and the brake device are disposed so that an angle formed between the brake pedal and the second direction is reduced according to depression of the brake pedal. Car brake structure. With a tension spring in the middle of the cable,
A contact portion for changing the extending direction of the cable from the pulley is provided on the body portion of the brake pedal, and an end portion of the cable can be engaged with a plate-like member provided on the body portion. The work vehicle brake structure according to any one of claims 2 to 4, further comprising a cable tension adjusting mechanism having a plurality of engagement holes with different distances from the contact portion.

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