JP4683569B2 - Pedal unit - Google Patents

Description

  The present invention relates to a pedal unit used for forward / reverse operation of a work vehicle or the like.

In a working vehicle such as a tractor that drives the drive wheels by shifting the power of the drive source via an HST (hydrostatic continuously variable transmission), a forward / reverse pedal that is operatively connected to the HST via a link mechanism is used. A configuration is known in which the HST output control amount can be manually manipulated (see, for example, Patent Document 1).
For example, in the configuration of Patent Document 1, a forward pedal and a reverse pedal, a forward side support shaft that supports the forward pedal, a reverse side support shaft that supports the reverse pedal, and a pair of support plates that face each other are provided. And a bracket configured to support both the forward-side support shaft and the reverse-side support shaft. The forward-side support shaft and the reverse-side support shaft are extended outward in the vehicle width direction. The forward pedal and the reverse pedal are respectively attached to the extending portions.
Since the forward pedal and the reverse pedal are generally arranged in parallel in the vehicle width direction, the pedal farther from the bracket exceeds the pedal closer to the bracket (by increasing the offset amount). ) Must be placed. Therefore, it is necessary to lengthen the support shaft of the far side pedal and / or the pedal arm that connects the pedal body and the support shaft.

However, if the pedal support shaft and the pedal arm are lengthened, the rigidity is lowered and the operation accuracy is lowered. For this reason, conventionally, measures have been taken, such as providing ribs or the like to the support shaft of the pedal on the far side to reinforce it, leading to an increase in the number of parts and an increase in assembly cost. In addition, in order to increase the rigidity, it is possible to use a member with higher strength or increase the diameter of the support shaft, etc., but in any case, the operation will increase due to the increase in cost and weight, which will increase the inertia. This is not preferable because accuracy may be reduced.
JP 2002-316550 A

  The present invention has been made in view of the above prior art, and an object of the present invention is to provide a pedal unit that can increase the strength of the pedal while suppressing an increase in cost.

  A pedal unit according to the present invention is a pedal unit for operating an output adjustment member of an HST provided in a work vehicle, and includes a forward pedal and a reverse pedal, a forward support shaft that supports the forward pedal, A reverse support shaft for supporting the reverse pedal; a pair of support plates facing each other; and a connecting member for connecting the pair of support plates, wherein the pair of support plates are the forward support shaft and the reverse drive shaft. Each of the support shafts, and one and the other of the both support shafts extend outward and inward in the vehicle width direction from the bracket, respectively. The forward pedal and the reverse pedal are respectively supported by the shaft and the extended portion of the reverse side support shaft.

According to the pedal unit configured as described above, the bracket is configured by connecting the pair of support plates by the connecting member, and the forward-side support shaft and the reverse-side support shaft are both supported by the pair of support plates constituting the bracket. The
One of the forward support shaft and the reverse drive shaft extends from the bracket outward in the vehicle width direction, and a pedal (forward pedal or reverse pedal) corresponding to the extending portion is supported. . Further, either the forward support shaft or the reverse drive shaft is extended inward in the vehicle width direction from the bracket, and a pedal corresponding to the extended portion is supported.

  In this way, the forward side support shaft supports the forward pedal in the extending portion that extends from the bracket to one side in the vehicle width direction, and the reverse side support shaft extends from the bracket with reference to the bracket. By supporting the reverse pedal in the extending portion extending to the opposite side of the portion, the maximum offset amount from the bracket of the forward pedal and the reverse pedal in the vehicle width direction is shortened compared to the conventional configuration. As a result, the strength of the pedal can be increased, and the size and cost can be reduced.

  Preferably, the bracket is fixed to one of a pair of step support frames supported by the chassis frame so as to be positioned on both left and right sides with respect to the driver's seat, and the forward pedal and the reverse pedal are: The one step support frame is arranged so as to be distributed in the vehicle width direction.

In this case, the pair of step support frames are supported on the chassis frame in a vibration-proof manner so as to be positioned on both the left and right sides with respect to the driver's seat. The bracket is fixed to one of the step support frames in a state where the forward pedal and the reverse pedal are distributed and arranged in the vehicle width direction across one of the step support frames.
Therefore, by supporting the bracket on the step support frame, the pedal arrangement can be easily arranged at a position where there is no sense of incongruity for the operator.

  More preferably, the bracket is configured to be positioned on the inner side in the vehicle width direction with reference to a step support frame to which the bracket is fixed.

In this case, the bracket is fixed in a state where the bracket is positioned on the inner side in the vehicle width direction of the step support frame.
Thereby, weight distribution can be collected in the center of the vehicle as much as possible by arranging the bracket as far as possible in the vehicle width direction while arranging the pedal position optimally. In addition, it is possible to prevent mud, grass, and the like wound up by the wheels of the work vehicle from entering the bracket.

  Preferably, the forward pedal is configured to be located on the inner side in the vehicle width direction than the reverse pedal.

  According to the pedal unit of the present invention, the forward support shaft supports the forward pedal in the extending portion that extends from the bracket to one side in the vehicle width direction, and the reverse travel support shaft moves forward with respect to the bracket. By supporting the reverse pedal in an extension portion that extends to the opposite side of the extension portion of the side support shaft, the bracket for the forward pedal and the reverse pedal in the vehicle width direction can be compared with the conventional configuration. The maximum offset amount of the pedal can be shortened, so that the strength of the pedal can be increased, and the size and cost can be reduced.

  Hereinafter, a preferred embodiment of a pedal unit according to the present invention will be described with reference to the accompanying drawings.

(A) Overall Configuration FIG. 1 is a schematic side view of a working vehicle 100 (here, a riding tractor) to which an example of a pedal unit 93 according to the present invention is applied, and FIG. 2 is a transmission in the working vehicle 100 of FIG. It is a schematic diagram.
As shown in FIG. 1, the working vehicle 100 includes a body frame 1, a drive source 2 supported by a front portion of the body frame, a transmission 3 coupled to a rear portion of the body frame 1, and a vehicle front A pair of left and right front wheels 4 disposed on the side, a pair of left and right rear wheels 5 disposed on the rear side of the vehicle, a bonnet 6 covering the drive source 2, and a driver seat 9 disposed behind the bonnet 6. It has.

FIG. 3 is a partially enlarged view of the vicinity of the driver seat 9. In FIG. 3, the cabin in the driver's seat 9 is deleted.
As shown in FIGS. 1 and 3, the body frame 1 includes a pair of left and right chassis frames 10 extending in the vehicle front-rear direction (A direction in FIG. 1) with a predetermined spacing in the vehicle width direction with respect to each other. And a pair of step support frames 120 respectively supported by the pair of chassis frames 10.

The chassis frame 10 supports the drive source 2 on the front side and is connected to the transmission 3 on the rear side.
The drive source 2 is supported in an anti-vibration manner on the front side of the chassis frame 10 via an anti-vibration member such as an anti-vibration rubber.
On the other hand, the transmission 3 is fixedly connected to the chassis frame 10 while being separated from the drive source 2 in the vehicle width direction.

The step support frame 120 supports the step base 12 serving as a driver's footrest space.
Preferably, in order to prevent vibrations associated with vehicle travel and / or vibrations from the drive source 2 supported by the chassis frame 10 to be vibration-proof, the step support frame 120 includes the corresponding chassis. The frame 10 is supported in an anti-vibration manner via an anti-vibration member such as elastic rubber.
In the present embodiment, as shown in FIG. 3, the step support frame 120 has a front mounting member provided on the front side fixed to the corresponding chassis frame 10 via an elastic member 121 and a rear side. A rear mounting member provided on the side is fixed to the transmission case 30 of the transmission 3 via an elastic member 121.

As shown in FIG. 2, the transmission 3 shifts the rotational power input from the drive source 2 and outputs it toward the rear wheel 5 acting as a main drive wheel and the front wheel 4 acting as a sub drive wheel. It is configured to be able to. In the present embodiment, the front wheel 4 is a steered wheel and the rear wheel 5 is a non-steered wheel.
Rotational power output from the transmission 3 toward the rear wheel 5 is differentially transmitted to a pair of left and right rear axles via a main drive wheel differential gear device 314 provided in the transmission 3. On the other hand, the rotational power output from the transmission 3 toward the front wheel 4 is transmitted to a differential gear device for auxiliary driving wheels disposed on the front side of the vehicle via a transmission shaft provided with universal joints at both ends. Then, differential transmission is performed from the differential gear device for auxiliary drive wheels to the pair of left and right front axles 4a.

In addition, the working vehicle 100 is configured to be provided with a working machine.
A PTO shaft 18 for outputting a driving force to the work machine when the work machine is attached is provided at the rear end of the mission case 30 so as to protrude rearward.

FIG. 4 is a schematic perspective view showing a frame configuration in the driving unit case 9 of the working vehicle 100 of FIG. In FIG. 4, the mission case 30 and the chassis frame 10 are omitted.
A steering column 92 is provided above the front end of the step support frame 120. Further, a step base 12 supported by a step support frame 120 is provided below and behind the steering column 92, and the rear wheel fender 11 and the driving unit frame 91 are provided behind the step base 12 and on the step support frame 120. Is provided. A driver seat (not shown) is disposed on the driver frame 91. That is, the driver's seat is positioned above the mission case 30.

  Below the step base 12, the forward and reverse pedals 931f and 931r of the pedal unit 93 provided on one side (here, the right side) of the pair of left and right step support frames 120 are located above the step base 12 through the opening 12h. It is arranged. Details will be described later.

(B) Transmission unit and transmission In the present embodiment, the drive source 2 and the transmission 3 are spaced apart from each other in the vehicle front-rear direction, and the transmission unit 200 includes the drive unit as shown in FIGS. It is provided on the source 2 side.
The transmission unit 200 is provided to output rotational power toward the subsequent transmission 3 at a position displaced from the output shaft 2 a of the drive source 2.

  That is, the transmission unit 200 includes an input shaft 210, an output shaft 220 disposed substantially parallel to the input shaft 210 at a position displaced downward with respect to the axial center position of the input shaft 210, an input shaft 210, and A gear transmission mechanism 230 capable of transmitting power to and from the output shaft 220 is provided, and the power from the drive source 2 is output toward the input shaft 31 of the transmission 3. Here, the drive shaft 2a in the drive source 2 is the input shaft 210 in the transmission unit 200 (directly connected to the input shaft 210), but indirectly to the input shaft 210 via a transmission mechanism. May be connected to each other.

In the present embodiment, the transmission unit 200 is configured to input rotational power from the drive source 2 via the flywheel 7.
The flywheel 7 includes a flywheel body 7a operatively connected to the output shaft 2a, an output portion 7c connected to the flywheel body 7a via a damper 7b, the flywheel body 7a and the output portion 7c. And a flywheel housing 13 surrounding the housing.
In the present embodiment, the flywheel housing 13 is connected to the drive source 2 on the upstream side in the transmission direction, and supports the transmission unit 200 on the downstream side in the transmission direction.

The transmission 3 is configured to input rotational power from the drive source 2 via the transmission unit 200.
In the present embodiment, the transmission 3 receives rotational power from the transmission unit 200 via the transmission shaft 17 with a universal joint.

  As shown in FIG. 2, the transmission 3 includes a traveling system transmission mechanism 310, a PTO system transmission mechanism 320, and a transmission case 30 that supports or accommodates the traveling system transmission mechanism 310 and the PTO system transmission mechanism 320. ing.

In the present embodiment, the traveling transmission mechanism 310 includes a hydrostatic continuously variable transmission (HST) 311 that functions as a main transmission, and a mechanical transmission 312 that functions as an auxiliary transmission.
The HST 311 is fluidly connected to a pump shaft 311a for inputting rotational power from the drive source 2 through the transmission unit 200, a hydraulic pump body 311b that is rotationally driven by the pump shaft 311a, and the hydraulic pump body 311b. A hydraulic motor main body 311c, a motor shaft 311d rotated by the hydraulic motor main body 311c, an HST housing 19 that houses the hydraulic pump main body 311b and the hydraulic motor main body 311c, and the hydraulic pump main body 311b. At least one of the hydraulic motor main body 311c is a variable displacement type. In the present embodiment, as shown in FIG. 2, the hydraulic pump body 311b is of a variable displacement type.

For example, the hydraulic pump body 311b is operatively connected to an output adjustment member 311e including a cradle type movable swash plate and a control shaft for tilting the movable swash plate, and a pedal unit 93 to be described later. A hydraulic servo mechanism (not shown) that receives the electrical signal output from the electrical detection means and controls the output adjusting member 311e based on the electrical signal.
In this case, the hydraulic servo mechanism is controlled to open and close the solenoid valve of the hydraulic servo mechanism based on an electric signal output from an electric detection means of a pedal unit 93 described later. The output adjustment member 311e that is operatively connected to the sway is controlled (movable swash plate angle is changed). Thereby, the volume in the hydraulic pump main body 311b is varied, and the drive control is performed.

The HST housing 19 is supported on the end face of the transmission case 30 on the upstream side in the transmission direction.
The pump shaft 311a has an end on the upstream side in the transmission direction forming an input end extending outward from the HST housing 19 and an end on the downstream side in the transmission direction extending into the transmission case 30. Thus, it is supported by the HST housing 19.
The motor shaft 311d is supported by the HST housing 19 so that an end on the downstream side in the transmission direction that forms an output end protrudes into the transmission case 30.

In the present embodiment, the traveling system transmission mechanism 310 includes a planetary gear unit 313 in addition to the HST 311 and the mechanical transmission device 312 in order to increase the speed change width.
The planetary gear device 313 forms an HMT in cooperation with the HST 311.
Specifically, the planetary gear device 313 functions as a first element for inputting constant speed power via the pump shaft 311a, a second element for inputting speed change power via the motor shaft 311d, and an output member. And a third element.
In the present embodiment, as shown in FIG. 2, the ring gear 313a constitutes the first element, the sun gear 313b constitutes the second element, and the carrier 313c constitutes the third element. .

As shown in FIG. 2, the mechanical transmission 312 has a drive shaft 312a, a driven shaft 312b, and a plurality of gear trains 312c, and any one of the plurality of gear trains 312c. Is selectively configured to transmit power, so that the rotational speed of the driven shaft 312b can be shifted in multiple stages with respect to the drive shaft 312a.
In the present embodiment, the mechanical transmission 312 is provided on the forward path in the hydraulic forward / reverse switching device X.
That is, in the present embodiment, as shown in FIG. 2, the traveling transmission mechanism 310 includes the hydraulic forward / reverse switching device X between the planetary gear unit 313 and the mechanical transmission 312. ing.
As shown in FIG. 2, the hydraulic forward / reverse switching device X includes a propeller shaft x1 operatively connected to an output member of the planetary gear device 313, and a clutch housing x2 supported by the propeller shaft x1 so as not to be relatively rotatable. A hollow forward drive member x3 supported rotatably on the propeller shaft x1, and a relative forward rotation of the propeller shaft x1 on the opposite side of the forward drive member x3 across the clutch housing x2. A supported reverse drive member x4, a forward drive state in which power is transmitted from the clutch housing x2 to the forward drive member x3, a reverse drive state in which power is transmitted from the clutch housing x2 to the reverse drive member x4, or the clutch Hydraulic pressure that can selectively take a neutral state in which power transmission from the housing x2 to the drive members x3 and x4 is cut off. And a latch x5.
The forward drive member x3 acts as the drive shaft 312a in the mechanical transmission 312.
As shown in FIG. 2, the reverse drive member x4 is operatively connected to a reverse gear y2 supported on the driven shaft 312b so as not to rotate relative to the driven shaft 312b via an idle gear y1.

  The rotational power output from the mechanical transmission 312 is differentially transmitted to the pair of main drive shafts (rear axles) 5a via the main drive wheel differential gear device 314.

Furthermore, in the present embodiment, as shown in FIG. 2, the traveling system transmission mechanism 310 includes a sub drive wheel power take-out device 315 in addition to the above-described configuration.
The auxiliary drive wheel power take-out device 315 transmits rotational power synchronized with rotational power output toward the main drive wheel (rear wheel) 5 via the auxiliary drive shaft (front axle) 4a. (Front wheel) 4 is configured to be able to output toward 4.

In the present embodiment, the auxiliary drive wheel power take-out device 315 includes a four-wheel drive state in which the auxiliary drive wheel 4 is driven in synchronization with the main drive wheel 5, and the auxiliary drive wheel 4 is moved to the main drive wheel 5. Further, the speed increasing state in which the speed is increased and the neutral state in which the output to the auxiliary driving wheel 4 is interrupted can be selectively taken.
Specifically, as shown in FIG. 2, the auxiliary drive wheel power take-out device 315 includes an input shaft z1 operatively connected to a main drive wheel transmission path from the drive source 2 to the main drive wheel 5, and An output shaft z2 for outputting power toward the auxiliary drive wheel 4, a clutch housing z3 supported so as not to rotate relative to the output shaft z2, and a synchronous drive member supported relative to the output shaft z2 so as to be rotatable relative to the output shaft z2. z4, a synchronous gear train z5 for operatively connecting the drive shaft z1 and the synchronous drive member z4, and the output shaft z2 on the opposite side of the synchronous drive member z4 across the clutch housing z3. A speed increasing side drive member z6 supported by the motor, a speed increasing side gear train z7 operatively connecting the drive shaft z1 and the speed increasing side drive member z6, and the clutch housing z3 to the synchronous side drive. A four-wheel drive state in which the clutch housing z3 is operatively engaged with the member z4, an acceleration state in which the clutch housing z3 is operatively engaged with the acceleration-side drive member z6, or the clutch housing z3 and the synchronization-side drive member z4 and the increase And a hydraulic clutch z8 that can selectively take a neutral state in which both speed-side drive members z6 are disconnected.

The PTO transmission mechanism 320 is configured to output the rotational power from the drive source 2 toward an attached work machine.
In the present embodiment, the PTO transmission mechanism 320 includes a PTO shaft 18 supported by the transmission case 30 so that rotational power can be output toward the work machine, and an input shaft of the transmission 3 (this embodiment). In the embodiment, it has a PTO hydraulic clutch unit 321 and a PTO transmission 322 inserted in a PTO transmission path from the pump shaft 311a) to the PTO shaft 18.

The PTO hydraulic clutch unit 321 has a driving side operatively connected to the pump shaft 311a and a driven side operatively connected to the PTO transmission 322.
In the present embodiment, as shown in FIG. 2, the PTO transmission mechanism 320 further includes a PTO hydraulic brake unit 323 that operates contrary to the PTO hydraulic clutch unit 321.
That is, the PTO hydraulic brake unit 323 is deactivated when the PTO hydraulic clutch unit 321 is in a power transmission state, and the PTO hydraulic clutch unit 321 is in a power cutoff state. The unit 321 is configured to apply a braking force to the driven side.

(C) Pedal unit Here, the pedal unit 93 of the present embodiment will be described in detail. 5 is a perspective view showing the arrangement of the pedal unit 93 in the present embodiment, FIG. 6 is an enlarged view of the pedal unit 93 in FIG. 5, and FIG. 7 is a plan view of the pedal unit 93 in FIG. 8 is a front view of the pedal unit 93 of FIG. 5, FIG. 9 is a left side view of the pedal unit 93 of FIG. 5 in the vehicle traveling direction, and FIGS. 10 to 12 are pedal units of FIG. FIG. 93 is a right side view of the vehicle traveling direction for explaining the operation of 93. 10 shows a neutral position, FIG. 11 shows a forward state, and FIG. 12 shows a reverse state. In addition, illustration is abbreviate | omitted suitably for the step stand 12, the 1st support plate 122a of the bracket 122, and the step support frame 120. FIG.

As shown in FIGS. 5 to 9, the pedal unit 93 supports the forward pedal 931f and the reverse pedal 931r that are manually operated, the forward-side support shaft 932f that supports the forward pedal 931f, and the reverse pedal 931r. Both the support shafts 932f and 932r are both supported so that the reverse drive shaft 932r, the forward drive shaft 932f, and the reverse drive shaft 932r are arranged side by side along the vehicle width direction. And a bracket 122.
The bracket 122 includes a pair of support plates (a first support plate 122a and a second support plate 122b) facing each other, and connecting members 122c1 and 122c2 that connect the pair of support plates 122a and 122b. The first support plate 122a and the second support plate 122b both support the forward support shaft 932f and the reverse support shaft 932r.
The first support plate 122a and the second support plate 122b are along the vehicle front-rear direction so as to face each other while being spaced apart from each other in the vehicle width direction.
In the present embodiment, the connection member includes a front connection member 122c1 that connects the first support plate 122a and the second support plate 122b on the front side, and the first support plate 122a and the second support plate on the rear side. And a rear connecting member 122c2 for connecting 122b.
In the present embodiment, the bracket 122 is a plate member that forms the first support plate 122a and a U-shaped bending member that is fixed to the plate member by welding or the like. The second support plate 122b, the front connecting member 122c1, and the rear connecting member 122c2 are integrally formed with a bending member.

The forward pedal 931f has a pedal body 9311f that is manually operated by the operator's feet, a base end portion supported on the forward-side support shaft 932f so as not to be relatively rotatable, and a distal end portion that supports the pedal body 9311f. Pedal arm 9312f.
The reverse pedal 932r has substantially the same configuration as the forward pedal 931f. Accordingly, in the figure, the same reference numerals with the end changed to “r” are attached, and detailed description thereof is omitted.
One end of the advancing support shaft 932f extends outward from one of the first support plate 122a or the second support plate 122b (the second support plate 122b in the illustrated form), and the bracket 93 It is supported by.
The pedal arm 9312f includes a first portion 9312f1 extending forward from the extending portion 933f of the advance side support shaft 932f, and a second portion 9312f2 extending upward from the distal end side of the first portion 9312f1. The pedal body 9311f is supported at the tip of the second portion 9312f2.

In the present embodiment, as shown in FIG. 7, the forward-side support shaft 932f and the reverse-side support shaft 932r are configured such that the extending portions 933f and 933r that support the corresponding pedals 931f and 931r are based on the bracket 93. Thus, both ends are supported by the first support plate 122a and the second support plate 122b in a state of extending in opposite directions.
That is, the forward support shaft 932f is supported at both ends by the first support plate 122a and the second support plate 122b in a state where the extending portion 933f supporting the forward pedal 931f extends to one side in the vehicle width direction. Has been. On the other hand, the reverse support shaft 932r is supported at both ends by the first support plate 122a and the second support plate 122b in a state where the extending portion 933r supporting the reverse pedal 931r extends to the other side in the vehicle width direction. It is supported.
In the present embodiment, as shown in FIG. 7, the forward support shaft 932f has an extension portion 933f extending inward in the vehicle width direction, and the reverse drive side support shaft 932r is an extension portion. 933r is extended outward in the vehicle width direction.
The forward and reverse pedals 931f and 931r supported by the extending portions 933f and 933r below the step base 12 are respectively connected to the pedal bodies 9311f and 9311r through the opening 12h of the step base 12 by the pedal arms 9312f and 9312r. It is supported in the state arrange | positioned above. A boot member 12b made of resin or the like is fitted into the opening 12h to prevent intrusion of mud or the like into the operation unit while avoiding a direct collision with the step base 12 of the pedal arms 9312f and 9312r. is doing.

  Thus, in the present embodiment, the forward support shaft 932f supports the forward pedal 931f at the extension portion 933f extending from the bracket 122 to one side in the vehicle width direction, and the reverse drive The side support shaft 932r supports the reverse pedal 931r at the extension portion 933r extending to the opposite side of the extension portion 933f of the advance side support shaft 932f with respect to the bracket 122. Accordingly, the maximum offset amount Smax from the bracket of the forward pedal 931f and the reverse pedal 931r in the vehicle width direction can be shortened as compared with the conventional configuration, and thereby the strength of the pedals 931f and 932r can be increased. At the same time, downsizing and cost reduction can be achieved.

More specifically, in the conventional configuration, as shown in FIG. 14, the forward-side support shaft 932f and the reverse-side support shaft 932r are both extended from the bracket 93 to the same side in the vehicle width direction, and both the extension portions 933f ′. 933r ′ support the forward pedal 931f and the reverse pedal 932r. In such a configuration, one of the forward pedal 931f and the reverse pedal 931r (the reverse pedal 931r in the example of FIG. 14) and the other (the forward pedal 931f in the illustrated example) are prevented from interfering with the vehicle from the bracket 93. Large offset in the width direction.
In such a conventional configuration, the entire pedal unit is increased in size, and it is necessary to provide the bracket with a strength that can support the pedal on the side that is largely offset in the vehicle width direction, resulting in an increase in cost.
On the other hand, in the present embodiment, as described above, the forward pedal 931f and the reverse pedal 931r are arranged in the vehicle width direction with the bracket 122 interposed therebetween. Both the offset amount of the pedal 931f and the reverse pedal 931r from the bracket 93 can be made as short as possible. Therefore, the entire pedal unit can be reduced in size, and the cost can be reduced by reducing the weight of the bracket 93 (see FIG. 13).

As shown in FIG. 6, the bracket 122 is fixed to one of the pair of step support frames 120 (here, the right side), thereby improving the maneuverability.
That is, as described above, the step support frame 120 is supported in an anti-vibration manner with respect to the chassis frame 10 (and the mission case 30), and the propagation of vibrations associated with vehicle travel or the like is reduced. Accordingly, by mounting the pedal unit 93 on the step support frame 120, the maneuverability with respect to the forward pedal 931f and the reverse pedal 931r can be improved.

  In the present embodiment, the bracket 122 has the one step support frame 120 so that the forward pedal 931f and the reverse pedal 931r are arranged in the vehicle width direction across the one step support frame 120. It is fixed to. In the present embodiment, in a state where the bracket 122 is fixed to the one step support frame 120, the forward pedal 931f is positioned inward in the vehicle width direction from the one step support frame 120, and the reverse drive The pedal 931r is configured to be located outward of the one step support frame 120 in the vehicle width direction.

By the way, the pedal unit 93 is fixed to the step support frame 120 supported by the chassis frame 10 in a vibration-proof manner as described above.
On the other hand, the HST 311 operated by the pedal unit 93 is supported by the mission case 30 as described above. Further, the HST 311 vibrates due to the pulsation of its own hydraulic pressure.
Thus, a vibration difference is generated between the pedal unit 93 and the HST 311. For this reason, when both are connected via a mechanical link mechanism as in the prior art, the control performance of the output adjusting member 311e by the pedal unit 93 deteriorates.
In this regard, in the present embodiment, the pedal unit 93 includes an electric detection mechanism that electrically detects an artificial operation amount of the forward pedal 931f and the reverse pedal 931r, and a detection signal from the electric detection mechanism. The output adjusting member 311e can be operated based on the above. The electric detection mechanism will be described later.

As shown in FIGS. 6 and 7, in the present embodiment, the bracket 122 is surrounded by the first support plate 122a, the second support plate 122b, the front connection member 122c1, and the rear connection member 122c2. The surrounding space is fixed to the step support frame 120 so as to be located on the inner side in the vehicle width direction from the corresponding step support frame 120. The bracket 122 is fixed to the step support frame 120 through the first support plate 122a. Specifically, the first support plate 122a includes a bearing region 122as that supports one end side of the forward-side support shaft 932f and the reverse-side support shaft 932r, and a mounting region that extends upward from the bearing region 122as. 122ah.
The bracket 122 having such a configuration is fixed to an end surface on the inner side in the vehicle width direction in a state where the attachment region 122ah of the first support plate 122a is inserted into the step support frame 120 having a hollow structure. Thus, the surrounding space is positioned on the inner side in the vehicle width direction from the step support frame 120.

By providing such a configuration, it is possible to effectively prevent mud or the like from entering the surrounding space where the forward support shaft 932f and the reverse drive shaft 932r, an electric detection mechanism described later, and the like are located. In addition, by supporting the bracket 122 on the step support frame 120, it is possible to easily arrange the pedal arrangement so that the pedal arrangement is optimized at a position where there is no sense of incongruity to the operator. Further, by arranging the bracket 122 as much as possible inside the vehicle width direction, the weight distribution can be collected at the center of the vehicle as much as possible.
On the other hand, the second support plate 122b has a bearing region that supports the other end side of the forward-side support shaft 932f and the reverse-side support shaft 932r at a position facing the bearing region. Further, the front connecting member 122c1 and the rear connecting member 122c2 connect the first support plate 122a and the second support plate 122b at substantially the same position in the vertical direction as the bearing region.

  In the present embodiment, the support plate 122a on the outer side in the vehicle width direction of the bracket 122 is formed larger than the support plate 122b on the inner side in the vehicle width direction. In particular, the support plate 122a has all the configurations of the pedal unit 93 except for the forward and reverse pedals 931f and 931r in the vehicle longitudinal direction, that is, the forward support shaft 932f, the reverse support shaft 932r, a neutral return mechanism described later, and electric detection. It extends over the location of the mechanism and neutral switch. Thereby, intrusion of mud, grass or the like can be further prevented. Note that the support plate 122b on the inner side in the vehicle width direction does not necessarily extend over the entire region as long as it extends over at least the positions where the forward support shaft 932f and the reverse support shaft 932r are disposed, as in this embodiment. Good.

In the present embodiment, the pedal unit 93 further includes a neutral return mechanism that returns the forward pedal 931f and the reverse pedal 931r to the neutral position when the manual operation force to the forward pedal 931f or the reverse pedal 931r is released. And an electric detection mechanism for detecting an artificial operation amount of the forward pedal 931f and the reverse pedal 931r.
The neutral return mechanism is supported by one of the forward support shaft 932f and the reverse drive shaft 932r (in this embodiment, the reverse drive shaft 932r, hereinafter referred to as a reference support shaft) so as not to be relatively rotatable. A reference member 9341 having a cam portion 934c and the other of the forward-side support shaft 932f or the reverse-side support shaft 932r (in this embodiment, the forward-side support shaft 932f; hereinafter, the other A connection mechanism 9345 that rotates the reference member 9341 around the reference support shaft as the support shaft 9345 rotates, and a pivot shaft 9343 that is substantially parallel to the forward support shaft 932f and the reverse drive shaft 932r. A swing member that is swingable and has a cam follower 934f that engages with the cam portion 934c, and the swing member 9342 is connected to the pivot shaft. And a neutral spring 9344 that biases the 343 around one side S1.
The reference member 9341 includes a bearing portion 9341s that is supported by the reference support shaft so as not to be relatively rotatable, and the cam portion 934c that extends radially outward from the bearing portion 9341s.
The cam portion 934c is located between the reference support shaft 932r and the other support shaft 932f with respect to the vehicle longitudinal direction position.

In the present embodiment, as shown in FIG. 9, the reference support shaft 932r and the other support shaft 932f are juxtaposed in the longitudinal direction of the vehicle at substantially the same position in the vertical direction. As shown in FIG. 9, the cam portion 934c is located between the reference support shaft 932r and the other support shaft 932f with respect to the vehicle longitudinal direction position, and with respect to the vertical position, the reference support shaft 932r and the other support shaft 932f. Is located above the support shaft 932f.
In the present embodiment, the cam portion 934c is provided with a cam shaft 934c1 that extends substantially parallel to the reference support shaft 932r, and a cam roller 934c2 that is rotatably supported by the cam shaft 934c1.

The reference member 9341 is further connected to the cam mechanism 934c so that the connection mechanism 9345 (the second link 9345b) is connected to a position displaced in the circumferential direction with respect to the axis of the reference support shaft 932r. Part 9341a.
In the present embodiment, the connecting portion 9341a is located below the cam portion 934c and between the reference support shaft 932r and the other support shaft 932f with respect to the vehicle longitudinal direction position.

The connecting mechanism 9345 includes the other support shaft 932f and the reference member 9341 so that the reference support shaft 932r rotates to the other side around the axis in accordance with the rotation of the other support shaft 932f around the axis. The connecting portion 9341a is operatively connected.
Specifically, the coupling mechanism 9345 has a base end portion supported by the other support shaft 932f so as not to rotate relative to the other support shaft 932f, and a distal end portion extending radially outward with reference to the axis of the other support shaft 932f. The first link 9345a includes a second link 9345b having a base end portion rotatably connected to the connecting portion and a tip end rotatably connected to the tip end of the first link 9345a. .
The first link 9345a has a virtual vertical plane Vf that passes through the axis of the other support shaft 932f when the forward pedal 931f and the reverse pedal 931r are positioned at neutral positions (in the state where no artificial operating force is applied). With the virtual horizontal plane Hf as a reference, the tip end portion is positioned on the side closer to the reference support shaft 932r than the virtual vertical plane Vf and above the virtual horizontal plane Hf.
On the other hand, the second link 9345b is a virtual vertical plane that passes through the axis of the reference support shaft 932r when the forward pedal 931f and the reverse pedal 931r are positioned at neutral positions (in the state where no artificial operating force is applied). With reference to Vr and the virtual horizontal plane Hr, the tip is positioned such that it is positioned closer to the other support shaft 932f than the virtual vertical plane Vr and above the virtual horizontal plane Hr. Yes.

The pivot shaft 9343 is supported by the first support plate 122a so as to be positioned in a gap between the bracket 122 and the step base 12 supported by the step support frame 120.
In the present embodiment, the pivot shaft 9343 is disposed substantially above the front connecting member 122c1 as shown in FIG.
The swing member 9342 includes a bearing portion 9342s that is supported by the pivot shaft 9343 so as to be rotatable about an axis, a first arm 9342a1 that extends from the bearing portion 9342s into the surrounding space, and the pivot shaft 9343. And a second arm 9342a2 extending to the opposite side of the first arm 9342a1 with reference to a virtual vertical plane V3 passing through the axis.

Here, the cam follower 934f is provided on the first arm 9342a1.
Specifically, as shown in FIG. 10, the cam follower 934f includes a neutral portion 934fn that engages with the cam portion 934c when the forward pedal 931f and the reverse pedal 931r are positioned at the neutral position, and the neutral portion. A forward cam driven surface extending from 934fn to one side, the forward cam driven surface 934ff engaging with the cam portion 934c when the forward pedal 931f is pressed, and the neutral portion 934fn interposed therebetween A reverse cam driven surface extending to the opposite side of the forward cam driven surface 934ff, and a reverse cam driven surface 934fr that engages with the cam portion 934c when the reverse pedal 931r is pressed. ing.
The forward cam follower surface 934ff is configured to be closer to the axis of the reference support shaft 932r as it is separated from the neutral portion 934fn.
Similarly, the reverse cam follower surface 934fr is configured to approach the axis of the reference support shaft 932r as the distance from the neutral portion 934fn increases.

The second arm 9342a2 extends toward the side opposite to the reference support shaft 932r with reference to a virtual vertical plane V3 passing through the axis of the pivot support shaft 9343.
The second arm 9342a2 functions as a connection portion of the neutral spring 9344 and also functions as a detection object of a neutral switch described later.

The neutral spring 9344 has a proximal end connected to the first support plate 122a and a distal end connected to the second support so as to urge the swinging member 9342 toward the one side S1 around the pivot shaft 9343. It is connected to the arm 9342a2.
Specifically, as shown in FIG. 9, the first support plate 122a has a front extension region 122af extending forward from the bearing region 122as and the attachment region 122ah.
A base end portion of the neutral spring 9344 is supported by the first support plate 122a in the front extension region 122af.

The neutral return mechanism having such a configuration operates as follows.
First, when the forward pedal 931f is artificially operated (depressed) from the neutral position in FIG. 10, the forward support shaft 932f rotates, and as shown in FIG. 11, the reference member 9341 interlocked with the forward support shaft 932f is moved. It is swung to one side F around the reverse side support shaft 932r which is the reference support shaft. At this time, the reverse pedal 931r supported by the reverse side support shaft 932r so as not to move relative to the reverse side support shaft 932r operates so as to rise from the neutral position with respect to the step base 12.

In addition, when the cam portion 934c moves to one side F around the reverse side support shaft 932r with the swing of the reference member 9341, the swing member 9342 is pushed up by the cam portion 934c of the reference member 9341, thereby the swing member 9342. Is swung around the pivot shaft 9343 to the other side S2. At this time, the cam portion 934c and the cam driven portion 934f slide relative to each other, and the engagement portion between the cam portion 934c and the cam driven portion 934f of the swinging member 9342 moves from the neutral portion 934fn to the forward contact surface 934ff. To do.
At this time, the urging member 9344 is pulled by the swinging of the swinging member 9342 around the pivot shaft 9343 toward the other side S2.

  Here, when the artificial operation of the forward pedal 931f is finished (depression is stopped), the swinging member 9342 is pivoted to the one side S1 around the second shaft 9343 by the pulled biasing member 9344. It is swung to one side S1. Along with this, the cam portion 934f of the reference member 9341 is rotated around the reverse side support shaft 932r to the other side R so as to return to the neutral position, and as a result, the forward and reverse pedals 931f and 931r are returned to the neutral position. The

  Next, when the reverse pedal 931r is operated (depressed) from the neutral position in FIG. 10 again, the reverse-side support shaft 932r rotates and, as shown in FIG. 12, the reverse-side support shaft 932r is provided so as not to be relatively movable. The reference member 9431 thus moved is swung to the other side R around the reverse side support shaft 932r. At this time, the forward-side support shaft 932f operatively connected to the reference member 9431 rotates with the swing of the reference member 9431, and the forward pedal 931f operates to rise from the neutral position to the step base 12. Yes.

Further, when the cam portion 934c moves to the other side R around the reverse side support shaft 932r as the reference member 9341 swings,
When the swing member 9342 is pushed up by the cam portion 934c of the reference member 9341, the swing member 9342 is swung around the pivot shaft 9343 to the other side S2. At this time, the cam portion 934c and the cam follower portion 934f slide with each other, and the engagement portion between the cam portion 934c and the cam follower portion 934f of the swinging member 9342 moves from the neutral portion 934fn to the reverse contact surface 934fr. To do.
At this time, the urging member 9344 is pulled by the swinging of the swinging member 9342 around the pivot shaft 9343 toward the other side S2.
In this way, the swinging member 9432 swings around the pivot shaft 9343 to the other side S2 against the biasing force of the biasing member 9344 regardless of which side the reference member 9341 swings around the reverse shaft 932r. Moved.

  Therefore, when the operation of the reverse pedal 931r is finished (depression is stopped), the forward and reverse pedals 931f and 931r are returned to the neutral position by the urging force of the urging member 9344 as in the case of the forward pedal 931f.

The electric detection mechanism is configured to detect the amount of human operation of both the forward pedal 931f and the reverse pedal 932r by detecting the movement of the reference member 9341 around the reference support shaft 932r. .
That is, as described above, the reference member 9341 swings to one side F around the reference support shaft 932r when the forward pedal 931f is pressed, and when the reverse pedal 931r is pressed. Rotates around the reference support shaft 932r to the other side R.
The electricity detection mechanism detects the amount of rotation of the reference member 9341 toward the one side F around the reference support shaft 932r as the operation amount of the forward pedal 931f, and the reference member 9341 as the operation amount of the reverse pedal 931r. The amount of rotation to the other side R around the reference support shaft 932r is detected.

As described above, by detecting the artificial operation amounts of the forward pedal 931f and the reverse pedal 931r as electric signals and enabling the operation amount to be transmitted to the output adjustment member 311e of the HST 311, the output adjustment member 311e of the HST 311 Mechanical connection with the forward pedal 931f and the reverse pedal 931r can be eliminated. Accordingly, if the neutral position adjustment by the neutral return mechanism 934 is performed only with respect to the forward pedal 931f and the reverse pedal 931r, the adjustment with respect to the HST 311 can be performed only by electrical setting, so the HST 311 and the forward / reverse pedal 931f, 931r can be assembled separately.
In addition, since the neutral neutral adjustment mechanism 934 need only be brought close to the forward / reverse pedals 931f and 931r by eliminating the need for mechanical neutral adjustment with respect to the HST 311, the bracket 122 on which the support shafts of the forward / reverse pedals 931f and 931r are supported. By supporting the neutral return mechanism 934, the configuration on the input side to the HST 311 can be configured as one unit.
Therefore, the number of parts can be reduced as much as possible, and the assembly efficiency can be improved.

  More specifically, the electricity detection mechanism in the present embodiment has a single electricity detection means 935 that can detect the rotation direction and the rotation amount of a potentiometer or the like.

In the present embodiment, the electricity detection means 935 indirectly detects the rotation direction and the rotation direction of the reference member 9341 around the reference support shaft 932r.
Specifically, the electricity detection mechanism has a detected link 9351 in addition to the electricity detection means 935.
The detected link 9351 is a detected shaft that rotates around the axis according to the rotation direction and the rotation amount of the reference member 9341 around the reference support shaft 932r, and is rotated around the axis by the electric detection means 935. And a detected shaft 9351s whose rotation amount can be detected.
Specifically, the detected link 9351 has a first arm 9351a1 extending upward from a bearing portion 9341s of the reference member 9341, a base end portion rotatably connected to the first link 9351a1, and A second arm 9351a2 having a tip extending forward, and a third arm 9351a3 having a base end rotatably connected to the tip of the second arm 9351a2 and having the detected shaft 9351s at the tip. Contains.

By providing the detected link 9351, the electric detection means 935 can be disposed in the dead space.
In the present embodiment, as shown in FIG. 7, the electricity detection means 935 is forward of the enclosed space of the bracket 122 and in the vehicle width direction with respect to the second arm 9342a2 of the swing member 9342 in the vehicle width direction. An attachment stay 9352 connected to the front connecting member 122c1 is positioned in a dead space between the pedal arm 9312f of the pedal (the forward pedal 931f in the present embodiment) located on the inner side. It is fixed.

Furthermore, in the present embodiment, the pedal unit 93 includes neutral detection means 936 that electrically detects the neutral positions of the forward pedal 931f and the reverse pedal 931r.
In the present embodiment, as shown in FIG. 9, the neutral detection means 936 detects a neutral position by contacting a detected body 9342p provided on the second arm 9342a2 of the swinging member 9342. Is configured to do.
That is, as described above, the swinging member 9342 swings to the other side S2 around the pivot shaft 9343 both when the forward pedal 931f is pressed and when the reverse pedal 931r is pressed. Move. Therefore, the neutral position of the forward pedal 931f and the reverse pedal 931r can be accurately detected by detecting the position of the detected body 9342p provided on the swing member 9342.
Examples of the neutral detection means 936 include a contact sensor and a push switch.
In the present embodiment, the neutral detection means 936 is configured to detect the neutral position by contacting the detected body 9342p, but of course, by being separated from the detected body. It can also be configured to detect a neutral position.

In the present embodiment, the detection object 9342p is provided at the tip of the second arm 9342a2, and the neutral detection means 936 is located in front of the electric detection means 935 and in the vehicle width direction. The first support plate 122a is positioned in a dead space between the two arms 9342a2 and the pedal arm 9312f of a pedal (in the present embodiment, the forward pedal 931f) positioned on the inner side in the vehicle width direction. It is supported by.
Further, according to the above configuration, since the amount of movement of the detected body 9342p can be increased with respect to the rotation angle of the reference member 9341 around the reference support shaft 932r, the neutral position can be detected more accurately. Can do.

Further, the pedal unit 93 includes a shock absorber 937 that prevents abrupt operation of the forward pedal 931f and the reverse pedal 932r.
More specifically, as shown in FIG. 9, the shock absorber 937 has a cylinder portion 937a fixed to the support plate 122a of the bracket 122 and a base end portion relative to the other support shaft (advance side support shaft) 932f. A plate member 932p that is supported immovably and has a distal end portion that extends radially outward with respect to the axis of the other support shaft 932f, a proximal end portion that is operatively connected to the plate member 932p, and a distal end portion that is A rod portion 937b (corresponding to a movable portion) inserted into the cylinder portion 937a, and the rod portion 937b swings as the other support shaft 932f swings, and the amount of insertion into the cylinder portion 937a changes. Is configured to do. A region partitioned by the cylinder portion 937a and the rod portion 937b is filled with air, oil, or the like, and can provide an impact buffering effect.
Since the other support shaft 932f and the reference support shaft (reverse side support shaft) 932r are operatively connected, not only the operation of the forward pedal 931f but also the operation of the reverse pedal 931r is the same as in the case of the forward pedal 931f. Can act on.

By using such a shock absorber 937, the forward pedal 931f and the reverse pedal 931r are gently rocked when returning to the neutral position.
Therefore, it is possible to prevent danger to the operator due to abrupt return of the forward and reverse pedals 931f and 931r, and it is possible to prevent a sudden change in the posture of the work vehicle 100 due to a sudden change in the operation state.

The shock absorber 937 of the present embodiment is provided below the pedal unit 93 while the axial directions of the cylinder portion 937a and the rod portion 937b are substantially parallel to the longitudinal direction of the bracket 122.
More specifically, the shock absorber 937 is disposed so as to overlap the forward-side support shaft 932f, the reverse-side support shaft 932r, the electrical detection means 935, and the neutrality detection means 936 when viewed from the bottom. Has been. Therefore, the shock absorber 937 can prevent mud etc. from entering the installation space of these members from below.
Specifically, the first support plate 122a has a lower extension region 122ab extending downward from the bearing region 122as and the front extension region 122af, and the cylinder portion 937a of the shock absorber 937 is a fixing member. It is supported by the downward extending region 122ab through 937h.

  By disposing the shock absorber 937 in this way, the operating capacity of the shock absorber 937 is sufficiently increased, and an increase in the size of the entire pedal unit 93 is avoided.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is not limited to the said embodiment, A various improvement, change, and correction are possible within the range which does not deviate from the meaning.

1 is a schematic side view of a working vehicle to which an example of a pedal unit according to the present invention is applied. It is a transmission schematic diagram in the work vehicle of FIG. FIG. 2 is a schematic side view of the periphery of a driving unit case of the working vehicle of FIG. 1. It is a schematic perspective view which shows the flame | frame structure in the operation part case of the working vehicle of FIG. It is a perspective view which shows arrangement | positioning of the pedal unit in this embodiment. It is an enlarged view of the pedal unit of FIG. It is a top view of the pedal unit of FIG. It is a front view of the pedal unit of FIG. FIG. 6 is a left side view of the pedal unit of FIG. 5 in the vehicle traveling direction. FIG. 6 is a right side view of the vehicle traveling direction at the neutral position of the pedal unit of FIG. 5. FIG. 6 is a right side view of the vehicle traveling direction in the forward state of the pedal unit of FIG. 5. FIG. 6 is a right side view of the vehicle traveling direction in a reverse state of the pedal unit of FIG. 5. It is a mimetic diagram for explaining pedal arrangement of a pedal unit concerning the present invention. It is a schematic diagram for demonstrating the pedal arrangement | positioning of the conventional pedal unit.

Explanation of symbols

9 ... Driver's seat 10 ... Chassis frame 93 ... Pedal unit 100 ... Working vehicle 120 ... Step support frame 122 ... Bracket 122a ... First support plate 122b ... Second support plate 122c1, 122c2 ... Connecting member 311 ... HST
311e ... Output adjusting member 931f ... Forward pedal 931r ... Reverse pedal 932f ... Advance side support shaft (other support shaft)
932r ... Reverse-side support shaft (reference support shaft)

Claims (4)

A pedal unit for operating an output adjustment member of an HST provided in a work vehicle,
With forward and reverse pedals,
A forward support shaft that supports the forward pedal;
A reverse support shaft for supporting the reverse pedal;
A pair of support plates facing each other and a connecting member for connecting the pair of support plates are provided, and the pair of support plates are configured to both support the forward-side support shaft and the reverse-side support shaft, respectively. With brackets,
One and the other of the both support shafts extend outward and inward in the vehicle width direction from the bracket, respectively.
The pedal unit, wherein the forward pedal and the reverse pedal are supported by the extending portions of the forward side support shaft and the reverse side support shaft, respectively. The bracket is fixed to one of the pair of step support frames supported by the chassis frame so as to be positioned on both the left and right sides with respect to the driver's seat,
2. The pedal unit according to claim 1, wherein the forward pedal and the reverse pedal are distributed and arranged in the vehicle width direction with the one step support frame interposed therebetween.   The pedal unit according to claim 2, wherein the bracket is positioned on the inner side in the vehicle width direction with reference to a step support frame to which the bracket is fixed.   The pedal unit according to any one of claims 1 to 3, wherein the forward pedal is located on the inner side in the vehicle width direction from the reverse pedal.

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