Seat lock structure and work machine with the same

Abstract

To surely fix a driver seat to a machine body.SOLUTION: A seat lock structure where an operator seat 6 swingably arranged on a seat support part around a horizontal axis is fixed to the seat support part in a swinging regulation state comprises: a fixing pin 58 which is arranged on a bottom face of the operator seat 6 and movable between an advance position and an exit position; an engaging member 51 which is arranged on a top face of the seat support part and engaged with the fixing pin 58 at the advance position; and a pressing member 60 which presses the fixing pin 58 in a moving direction to the advance position. The engaging member 51 includes: an engagement hole 59 into which the fixing pin 58 at the advance position is inserted to regulate upper oscillation of the operator seat 6; and a slant guide face 74 which contacts with a tip part of the fixing pin 58 at the advance position when the operator seat 6 oscillates downward, and guides the tip part into the engagement hole 59 while moving the fixing pin 58 against the pressing power to the exit position in accompany with the downward oscillation of the operator seat 6. The tip part of the fixing pin 58 perform point contact or line contact with the guide face 74.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a seat lock structure for fixing a driver's seat in a state in which the swinging of the driver's seat is restricted in a working machine such as a backhoe, and to a working machine equipped with the seat lock structure. [Background technology]

[0002] Conventionally, there is known a driver's seat for a work vehicle as disclosed in Patent Document 1. In the driver's seat disclosed in Patent Document 1, a seat support member is attached so as to be freely swingable up and down around a lateral axis near the front end, and in a work vehicle in which a seat is attached to the seat support member, a cam surface is formed on the tip side of a locking member attached to the seat support member, and after the lock pin is pushed by the cam surface against a spring as the seat support member swings downward, the cam surface is positioned relative to the lock pin so that the lock pin fits into an engagement hole of the locking member by the spring, thereby making it possible to fix the seat support member in a seated seat support posture. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-186791 Summary of the Invention [Problem to be solved by the invention]

[0004] When providing a seat lock structure, a structure that allows the driver's seat to be easily fixed to the aircraft body is required. For example, the seat lock structure is preferably a structure that allows the driver's seat to be reliably fixed to the aircraft body by the driver's seat's own weight.

[0005] However, the structure of Patent Document 1 does not take into consideration the specific structure of the contact portion between the lock pin and the cam surface, so it is necessary to apply a large external force to swing the driver's seat downward to a position where the lock pin fits into the engagement hole of the locking member while the cam surface presses the lock pin against the spring.

[0006] In view of the above problems, the present invention aims to provide a seat lock structure that can easily fix a driver's seat to the body of a work machine in which the driver's seat is freely swingable, and a work machine equipped with a seat lock structure. [Means for solving the problem]

[0007] The seat lock structure of the present invention is a seat lock structure that fixes a driver's seat, which is arranged to be freely swingable around a horizontal axis relative to a seat support part, in a state in which swinging relative to the seat support part is restricted, and includes a fixed pin that is arranged on the bottom surface of the driver's seat and moves between two points, an advanced position and a retracted position, an engaging member that is arranged on the upper surface of the seat support part and engages with the fixed pin at the advanced position, and a biasing member that applies a biasing force to bias the fixed pin in a direction to move it to the advanced position, the engaging member having an engaging hole that is inserted when the fixed pin is in the advanced position to restrict the upward swing of the driver's seat, and an inclined guide surface that comes into contact with the tip of the fixed pin in the advanced position when the driver's seat is swung downward, and guides the tip to the engagement hole while moving the fixed pin against the biasing force in the direction of the retracted position as the driver's seat swings downward, and the tip of the fixed pin makes point contact or line contact with the guide surface. Effect of the Invention

[0008] According to the above-described seat lock structure, the sliding resistance between the tip of the fixing pin and the guide surface can be reduced, so that the driver's seat can be easily fixed to the aircraft body. [Brief description of the drawings]

[0009] [Figure 1] FIG. [Diagram 2] FIG. 2 is an overall perspective view of the working machine as viewed from the right front. [Diagram 3] FIG. [Figure 4] This is an oblique view of the aircraft body and the driver's seat from the front right. [Diagram 5] FIG. 2 is a perspective view of the bonnet and the support frame as viewed from the right front. [Figure 6] FIG. 2 is a perspective view of the driver's seat and the support frame as viewed from the right front. [Figure 7] FIG. 2 is a front view of the driver's seat and the support frame as viewed from the front. [Figure 8] FIG. 4 is a side view of the driver's seat and the support frame as viewed from the right. [Figure 9] FIG. 2 is a top view of the fixing pin and the intermediate support plate from the lower right. [Figure 10] 4 is a cross-sectional view of the fixing pin and the intermediate support plate taken along the up-down and front-rear directions. FIG. [Figure 11] This is an overhead view of the top surface of the support frame from the upper right. [Figure 12] 1A is a cross-sectional view showing a state in which the tip of the fixing pin makes line contact with the guide surface, and FIG. 1B is a cross-sectional view showing a state in which the tip of the fixing pin makes point contact with the guide surface. [Figure 13] FIG. 4A is a perspective view showing the rotation prevention mechanism, and FIG. 4B is a cross-sectional view showing the rotation prevention mechanism. [Figure 14] FIG. 13 is a right side view showing an operation of releasing the seat lock structure and swinging the driver's seat relative to the bonnet. [Figure 15] 11 is a right side view showing an operation for restricting the rocking of the driver's seat relative to the bonnet in the seat lock structure. FIG. [Figure 16] 11 is a right side view showing an operation for releasing the restriction on the rocking of the driver's seat relative to the bonnet in the seat lock structure. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] Fig. 1 is a side view showing the overall configuration of a working machine 1 according to this embodiment. Fig. 2 is a perspective view showing the overall configuration of the working machine 1 according to this embodiment. In this embodiment, a backhoe, which is a rotating working machine, is exemplified as the working machine 1. The working machine 1 is not limited to a backhoe, and may be another working machine such as a tractor.

[0012] As shown in Figures 1 and 2, the work machine 1 is equipped with a machine body (swivel base) 2, a traveling device 3, and a work device 4. The machine body 2 is equipped with a driver's seat 6 where an operator sits, and a four-post type ROP 15. The ROP 15 is of canopy type having a roof 19.

[0013] In this embodiment, the direction toward the front of an operator seated in the driver's seat 6 of the work machine 1 (the direction of the arrow A1 in FIG. 1) will be described as the forward direction, the direction toward the rear of the operator (the direction of the arrow A2 in FIG. 1) as the rear direction, and the direction of the arrow A3 in FIG. 1 as the front-rear direction. Also, the direction toward the left of the operator (the front in FIG. 1) will be described as the leftward direction, and the direction toward the right of the operator (the back in FIG. 1) will be described as the rightward direction.

[0014] Further, a direction perpendicular to the front-rear direction A3 and parallel to the horizontal direction will be described as a fuselage width direction.

[0015] A bonnet 14 that covers mounted items such as the prime mover (engine) is provided at the rear of the machine body 2. A weight 25 for achieving weight balance with the working device 4 is disposed under the bonnet 14 at the rear of the machine body 2. The working machine 1 of this embodiment is a small backhoe, and a driver's seat 6 is disposed above the prime mover (prime mover room).

[0016] As shown in Fig. 3, the prime mover 91 is mounted in the center in the width direction at the rear of the body 2. The prime mover 91 is disposed below the driver's seat 6. A cooling fan 100, a radiator 92, and an oil cooler 93 are disposed to the left of the prime mover 91. A hydraulic pump 95 is disposed to the right of the prime mover 91. The prime mover 91, the cooling fan 100, the radiator 92, the oil cooler 93, and the hydraulic pump 95 are housed in a prime mover room 91A provided inside the bonnet 14.

[0017] The bonnet 14 is disposed at the rear of the body 2. A prime mover room 91A (see FIG. 3) in which the prime mover 91 and the like are stored is formed inside the bonnet 14. The bonnet 14 is formed in a box shape by combining plate members of a first cover body 101A to a fourth cover body 101D (see FIG. 5). The bonnet 14 also has therein a bonnet support frame 98 that supports the first cover body 101A to the fourth cover body 101D (see FIG. 4).

[0018] As shown in FIGS. 4 and 5, the first cover body 101A covers the front and the upper part of the motor 91. The first cover body 101A has a front wall 101Aa located in front of the prime mover 91, and an upper wall 101Ab located above the prime mover 91. An inspection opening 99 for inspecting the prime mover 91 housed in the bonnet 14 is formed in the upper wall 101Ab.

[0019] 3, the second cover body 101B is disposed behind the first cover body 101A and the prime mover 91. The third cover body 101C covers the prime mover 91, the cooling fan 100, the radiator 92, the oil cooler 93, etc. from the left side. The fourth cover body 101D covers the prime mover 91, the hydraulic pump 95, etc. from the right side.

[0020] Among the first cover body 101A to the fourth cover body 101D, the second cover body 101B and a part of the third cover body 101C can be opened and closed freely, which allows the prime mover 91, radiator 92, oil cooler 93, and hydraulic pump 95 housed inside the prime mover room 91A to be approached from the rear or left side for maintenance.

[0021] As shown in FIG. 4, a bonnet support frame 98 is disposed inside the bonnet 14, which supports the first cover body 101A to the fourth cover body 101D.

[0022] The bonnet support frame 98 is formed in an upright shape extending upward from the swivel base plate 5, and has a skeletal structure in which a number of rod-shaped frame members are combined vertically and horizontally. A floor section 21 is provided in front of the bonnet support frame 98. The bonnet support frame 98 has a lower frame 98B arranged below the floor section 21, and an upper frame 98T arranged above the floor section 21.

[0023] The lower frame 98B has a first lower frame 98B1 provided below the left front part of the driver's seat 6, a second lower frame 98B2 provided below the right front part of the driver's seat 6, a third lower frame 98B3 provided below the left rear part of the driver's seat 6, and a fourth lower frame 98B4 provided below the right rear part of the driver's seat 6. The first lower frame 98B1 to the fourth lower frame 98B4 are all rod-shaped frames and are arranged to stand upright from the swivel base plate 5. The first lower frame 98B1 to the fourth lower frame 98B4 are arranged at a distance from each other in the front-rear or left-right direction.

[0024] The upper frame 98T is a rod-shaped member disposed continuously above the lower frame 98B. There are four upper frames 98T, like the lower frames 98B. The four upper frames 98T are a first upper frame 98T1, a second upper frame 98T2, a third upper frame 98T3, and a fourth upper frame 98T4. The four upper frames 98T are disposed at a distance from each other in the front-rear or left-right direction. The upper frames 98T and the lower frames 98B are disposed at the four horizontal corners (front left, front right, rear left, and rear right corners) of the support frame 98, respectively.

[0025] The first upper frame 98T1 and the second upper frame 98T2 are disposed with a gap in the left-right direction. The first upper frame 98T1 and the second upper frame 98T2 are formed in a shape that extends in the up-down direction, is bent backward at the upper end, and extends horizontally to the rear end along the front-rear direction (approximately L-shaped in a side view).

[0026] A first connecting frame 102 extending horizontally along the left-right direction is provided between the lower end of the first upper frame 98T1 and the lower end of the second upper frame 98T2. The first connecting frame 102 connects the lower end of the first upper frame 98T1 and the lower end of the second upper frame 98T2 in the left-right direction.

[0027] A second connecting frame 103 extending in the left-right direction is provided between the portion bent toward the rear of the first upper frame 98T1 (the front end of the upper portion) and the portion bent toward the rear of the second upper frame 98T2 (the front end of the upper portion). The second connecting frame 103 connects the upper end of the first upper frame 98T1 and the upper end of the second upper frame 98T2 in the left-right direction.

[0028] A third connecting frame 104 extending in the left-right direction is provided between the rear end (rear end of the upper part) of the first upper frame 98T1 and the rear end (rear end of the upper part) of the second upper frame 98T2. The third connecting frame 104 connects the rear end of the first upper frame 98T1 and the rear end of the second upper frame 98T2 in the left-right direction.

[0029] The bonnet support frame 98 is a three-dimensional lattice-like framework with high rigidity that is attached to the upper part of the rotating base plate 5 by combining frame members that are extended in the vertical, front-rear, or left-right directions in a vertical and horizontal manner. The driver's seat 6 is supported above the bonnet support frame 98 via the bonnet 14. By supporting the driver's seat 6 on such a high-rigidity bonnet support frame 98, the driver's seat 6 can be reliably and firmly supported above the rotating base plate 5.

[0030] As shown in FIG. 4, FIG. 5, and FIG. 11, an upper wall (seat support portion) 101Ab of the first cover body 101A is disposed above the bonnet support frame 98. The upper wall 101Ab of the first cover body 101A is disposed below the seat lock structure 50 described later, and supports the seat lock structure 50 from below. The upper wall 101Ab is disposed below the engaging member 51 described later, and serves as a support plate 52 that supports the engaging member 51 from below. As shown in FIG. 4 and FIG. 11, an opening 98H that is rectangular when viewed from above is formed in the upper part of the support frame 98. This opening 98H is surrounded by four members: a first upper frame 98T1 (an upper part of the first upper frame 98T1) extending in the front-rear direction, a second upper frame 98T2 (an upper part of the second upper frame 98T2) extending in the front-rear direction, and a second connecting frame 103 and a third connecting frame 104 extending in the left-right direction. A reinforcing frame 120 is disposed above the opening 98H and is disposed around the front wall 101Aa and the upper wall 101Ab of the first cover body 101A. The upper wall 101Ab (support plate 52) is fixed to the reinforcing frame 120 by means of bolt fastening or the like.

[0031] The seat support portion is a member that supports the seat lock structure 50 relative to the aircraft body 2. The seat lock structure 50 of this embodiment uses the upper wall 101Ab (support plate 52) of the first cover body 101A as the seat support portion. However, the seat support portion of the present invention is not limited to a plate member such as the support plate 52, nor is it limited to a member that constitutes the bonnet 14. For example, a member separate from the bonnet 14 may be provided as the seat support portion, and the seat lock structure 50 may be supported relative to the aircraft body 2 using the separate member. In this case, the seat support portion that supports the seat lock structure 50 does not have to be a plate member.

[0032] As shown in Fig. 4, an inspection hatch 99 for inspecting the interior surrounded by the bonnet support frame 98 (the interior of the motor room 91A) is formed in the right central portion of the upper wall 101Ab (support plate). The inspection hatch 99 is closed by a cover member 106. The cover member 106 is detachably disposed in the inspection hatch 99 using fasteners 107 (three thumb screws in the illustrated example). Therefore, by removing the cover member 106, the interior of the motor room 91A can be inspected through the inspection hatch 99.

[0033] An engagement member 51 of a seat lock structure 50, which will be described later, is provided on the central left part of the upper wall 101Ab (support plate 52). The engagement member 51 is disposed to the left of the inspection hatch 99 and spaced apart from the inspection hatch 99 in the left-right direction.

[0034] Mount members 53 that elastically support the driver's seat 6 (more precisely, the driver's seat 6 via the intermediate support plate 83) are provided at the rear of the upper wall 101Ab. The mount members 53 are members that include an elastic body such as rubber. The mount members 53 are formed in a short cylindrical shape with an axis oriented in the vertical direction. The mount members 53 are provided at the left and right parts of the rear of the upper wall 101Ab.

[0035] Next, the driver's seat 6 and the intermediate support plate 83 that supports the driver's seat 6 from below will be described.

[0036] As shown in Fig. 14, the driver's seat 6 can be swung around a support shaft 54c provided at the front of the driver's seat 6, around a horizontal axis relative to the upper wall 101Ab of the support frame 98. When the driver's seat 6 swung around the support shaft 54c, the rear part of the driver's seat 6 moves away from or toward the upper wall 101Ab. As shown in Figs. 8 and 9, the intermediate support plate 83 is fixed to the bottom part of the driver's seat 6, and swings integrally with the driver's seat 6. The intermediate support plate 83 will be described later. When the driver's seat 6 and the rear part of the intermediate support plate 83 are swung relative to the support frame 98, the attitudes of the driver's seat 6 and the intermediate support plate 83 are changed.

[0037] Specifically, as can be seen from the change in posture from the left to the right in Fig. 14, the rear parts of the driver's seat 6 and the intermediate support plate 83 swing in the flip-up direction (upward) relative to the front parts. The driver's seat 6 can also change its posture from the right to the left in Fig. 14. In other words, the driver's seat 6 can swing in the flip-up direction (upward) and the push-down direction (downward).

[0038] In the following explanation, the position shown in the left diagram of Fig. 14 will be referred to as the "horizontal position H," and the position shown in the right diagram of Fig. 14 will be referred to as the "flip-up position S." Figs. 4 to 10 show the driver's seat 6 in the "horizontal position H," and when Figs. 4 to 10 are used, the positions of the driver's seat 6 and the intermediate support plate 83 will be explained based on the "horizontal position H."

[0039] As shown in Fig. 4, the driver's seat 6 is disposed above the inspection hatch 99. When the driver's seat 6 is in a horizontal position (seated position) H, the upper part of the inspection hatch 99 is covered by the driver's seat 6, so the inspection hatch 99 cannot be accessed. When the position of the driver's seat 6 is changed from the horizontal position H to the lifted position S, the inspection hatch 99 becomes uncovered by the driver's seat 6 (exposed state), so the inspection hatch 99 can be accessed.

[0040] As shown in FIG. 4 and FIG. 6 to FIG. 8, the driver's seat 6 has a seat portion 6A and a backrest portion 6B. The seat portion 6A is a portion on which the operator sits (rests his / her buttocks and thighs). The backrest portion 6B is a portion on which the seated operator leans his / her back. The backrest portion 6B is provided so as to extend upward or upward from the rear portion of the seat portion 6A. An angle adjustment lever 108 capable of adjusting the inclination angle of the backrest portion 6B is provided on the right side surface of the backrest portion 6B. A weight adjustment knob 109 is provided on the right end portion of the rear portion of the seat portion 6A. The weight adjustment knob 109 adjusts the repulsive force of the spring in the seat portion 6A, etc. The comfort of sitting on the seat portion 6A is adjusted by rotating the weight adjustment knob 109.

[0041] 7 and 8, the intermediate support plate 83 is a plate member disposed below the seat portion 6A so as to be approximately parallel to the bottom surface 6C of the seat portion 6A. In the "horizontal position H", the front end of the intermediate support plate 83 is bent at approximately a right angle so as to hang down downward.

[0042] The upper and lower parts of the intermediate support plate 83 have different functions. The upper part of the intermediate support plate 83 has a function of sliding the driver's seat 6 in the front-rear direction relative to the intermediate support plate 83. In order to achieve this sliding function, a slide mechanism 80 is provided on the upper part of the intermediate support plate 83. The lower surface of the intermediate support plate 83 has a function of rocking the intermediate support plate 83 and the driver's seat 6 provided on the upper part of the intermediate support plate 83. In order to achieve this rocking function, a rocking mechanism 54 is provided on the lower part of the intermediate support plate 83.

[0043] 7 and 8, the slide mechanism 80 supports the driver's seat 6 so as to be slidable in the front-rear direction relative to an intermediate support plate 83. The slide mechanism 80 is disposed between a bottom surface 6C of the seat portion 6A and the intermediate support plate 83. The slide mechanism 80 has a first slide mechanism 81 provided on the left part of the bottom surface 6C and having a first slide rail 84, a first slider 85, and a first bearing 86, and a second slide mechanism 82 provided on the right part of the bottom surface 6C and having a second slide rail 87, a second slider 88, and a second bearing 89.

[0044] 6 to 11 supports the intermediate support plate 83 and the driver's seat 6 supported by the intermediate support plate 83 so as to be freely swingable about an axis facing in the left-right direction. The swing mechanism 54 of this embodiment swings the rear part of the driver's seat 6 about a support shaft 54c extending in the left-right direction and provided at the front part of the driver's seat 6. As shown in FIGS. 9 and 11, the swing mechanism 54 has a base body 54a provided on the second connecting frame 103 of the support frame 98, a swing body 54b provided on the lower surface of the intermediate support plate 83, and a support shaft 54c communicating between the base body 54a and the swing body 54b.

[0045] As shown in Fig. 11, the base body 54a has a left base piece 54aL and a right base piece 54aR that are provided at a distance in the left-right direction in the middle of the second connecting frame 103 in the left-right direction. The left base piece 54aL and the right base piece 54aR are plate members that are approximately triangular in a side view. A left insertion hole 55L through which the shaft 54c is inserted in the left-right direction is formed in the center of the left base piece 54aL. A right insertion hole 55R through which the shaft 54c is inserted in the left-right direction is formed in the center of the right base piece 54aR.

[0046] The second connecting frame 103 has a cross section that is curved so as to rise toward the upper front when cut perpendicularly to the left-right direction. The left base piece 54aL and the right base piece 54aR are both attached to the curved front surface (upper surface) of the second connecting frame 103 so as to rise toward the upper front.

[0047] 9, the rocking body 54b is provided along a portion bent downward at the front end of the intermediate support plate 83. The rocking body 54b is made up of a left rocking piece 54bL provided on the left part of the front end of the intermediate support plate 83 and a right rocking piece 54bL provided on the right part of the front end of the intermediate support plate 83. The left swing piece 54bL and the right swing piece 54bR are attached so as to stand downward from the lower surface of the intermediate support plate 83. The left swing piece 54bL and the right swing piece 54bR are provided so as to extend along the front-rear direction. An insertion hole 56 is formed in the center of the left swing piece 54bL and the right swing piece 54bR so as to penetrate along the left-right direction. The support shaft 54c is inserted through the insertion hole 56.

[0048] The support shaft 54c is a shaft that communicates in the left-right direction between the left base piece 54aL and the right base piece 54aR of the base body 54a and the left swinging piece 54bL and the right swinging piece 54bR of the swinging body 54b. A head portion having a diameter larger than the opening diameters of the left insertion hole 55L, the right insertion hole 55R, and the insertion hole 56 is provided at the right end of the support shaft 54c. A retaining pin 57 that prevents the support shaft 54c from coming out of the left insertion hole 55L, the right insertion hole 55R, and the insertion hole 56 is provided at the left end of the support shaft 54c.

[0049] The above-mentioned rocking mechanism 54 supports the rocking body 54b provided on the lower surface of the intermediate support plate 83 so as to be rockable about a support shaft 54c extending in the left-right direction with respect to a base body 54a provided on the second connecting frame 103 of the bonnet support frame 98. As a result, the intermediate support plate 83 and the driver's seat 6 supported by the intermediate support plate 83 can have their rear portion rockable in the up-down direction with their front portion, on which the support shaft 54c is provided, as the center.

[0050] Now, as shown in Figures 8 and 10, a seat lock structure 50 is provided between the upper wall 101Ab of the bonnet support frame 98 and the intermediate support plate 83, which fixes the driver's seat 6 in a state in which its rocking (upward rocking) relative to the bonnet 14 is restricted.

[0051] The seat lock structure 50 has a fixing pin 58 arranged on the bottom surface 6C of the driver's seat 6 and an engaging member 51 arranged on the upper surface (upper wall 101Ab) of the bonnet 14. The fixing pin 58 is movable between two points, an advanced position P1 (see FIG. 15(d)) and a retracted position P2 (see FIG. 16(b)). The engaging member 51 has an engaging hole 59 that engages with the fixing pin 58. When the fixing pin 58 is moved to the advanced position P1 (see FIG. 15(d)), the fixing pin 58 engages with the engaging hole 59 of the engaging member 51. On the other hand, when the fixing pin 58 is moved to the retracted position P2 (see FIG. 16(b)), the fixing pin 58 goes out of the engaging hole 59 of the engaging member 51, and the tip of the fixing pin 58 does not engage with the engaging hole 59. In other words, as shown in Figures 15 and 16, by moving the tip of the fixing pin 58 between the two points, the advanced position P1 and the retracted position P2, the seat lock structure 50 switches between an engaged state RS (see Figures 15 and 16) in which the fixing pin 58 engages with the engaging member 51, and a disengaged state US (see Figures 15 and 16) in which the fixing pin 58 does not engage with the engaging member 51.

[0052] The seat lock structure 50 includes a biasing member 60 that biases the fixed pin 58 in a direction (rearward) in which the fixed pin 58 moves to the advanced position P1. As described below, in this embodiment, the biasing member 60 is a coil spring. The biasing member 60 biases the fixed pin 58 toward the advanced position P1, thereby maintaining the seat lock structure 50 in the engaged state RS. In other words, to put the seat lock structure 50 into the disengaged state US, the fixed pin 58 must be moved to the retracted position P2 against the biasing force of the biasing member 60.

[0053] When the seat lock structure 50 is in the engaged state RS, the driver's seat 6 is fixed in a state in which its rocking relative to the bonnet 14 is restricted. When the seat lock structure 50 is in the disengaged state US, the restriction on the rocking of the driver's seat 6 relative to the bonnet 14 is released, and the driver's seat 6 can rock.

[0054] Next, the fixing pin 58, the engaging member 51, and the biasing member 60 provided in the seat lock structure 50 will be described in detail.

[0055] As shown in Figures 9 and 10, the fixing pin 58 is a rod-shaped member extending in the front-rear direction, and is attached to the central left part of the lower surface of the intermediate support plate 83. The base end (front end) of the fixing pin 58 is bent upward below the front end of the intermediate support plate 83. The base end (front end) of the fixing pin 58 bent upward extends to a position further forward and above the front end of the intermediate support plate 83. The base end (front end) of the fixing pin 58 is bent at a right angle in the horizontal direction (to the right in the illustrated example). The base end (front end) of the fixing pin 58 bent at a right angle forms a disengagement lever that moves the fixing pin 58 from the advanced position P1 to the retracted position P2 when pulled. The disengagement lever 61 is a part that is gripped when pulling the fixed pin 58 forward in order to change the seat lock structure 50 from an engaged state to a disengaged state. By using the disengagement lever 61 in which the base end of the fixed pin 58 is bent at a right angle, it becomes easier for the operator to grip the fixed pin 58, and the fixed pin 58 can be easily pulled between the advanced position P1 and the retracted position P2.

[0056] The tip (rear end) of the fixing pin 58 extends to approximately the center in the front-to-rear direction of the intermediate support plate 83. The tip (rear end) of the fixing pin 58 is formed in a shape that tapers toward the front (rear) so that it can be easily inserted into the engagement hole 59 of the engagement member 51. The tip (rear end) of the fixing pin 58 is angularly chamfered or rounded so that it can come into line contact or point contact with a guide surface 74 of the engagement member 51, which will be described later. The shape of the tip (rear end) of the fixing pin 58 will be described in detail later.

[0057] As shown in FIG. 10, the midpoint of the fixing pin 58 in the front-rear direction is guided so as to be freely movable in the front-rear direction by a first front-rear guide portion 62 and a second front-rear guide portion 63 arranged at a distance in the front-rear direction.

[0058] As shown in Figs. 10 and 13, a notch 66 is formed in the front of the intermediate support plate 83. The first front-rear guide portion 62 is a hole formed in the first guide piece 64 that hangs down from the opening edge at the rear of the notch 66. A vertical through portion 67 that is an opening that passes through the intermediate support plate 83 in the vertical direction is formed in the middle of the front-rear direction of the intermediate support plate 83. The second front-rear guide portion 63 is a hole formed in the second guide piece 65 that hangs down from the opening edge at the front of the vertical through portion 67. The middle portion of the fixing pin 58 in the front-rear direction is inserted through the first front-rear guide portion 62 and the second front-rear guide portion 63.

[0059] Next, the cutout portion 66 and the vertical through-hole portion 67 will be described.

[0060] 13, the notch 66 is formed by cutting out the front end of the intermediate support plate 83 bent downward in the up-down direction. The notch 66 extends horizontally from the front end of the intermediate support plate 83 toward the rear. By providing such a notch 66, the front end of the intermediate support plate 83 bent downward does not exist in front of the base end (front end) of the fixing pin 58. Therefore, the base end (front end) of the fixing pin 58 can be extended forward of the intermediate support plate 83 while avoiding interference with the front end of the intermediate support plate 83 bent downward.

[0061] As shown in Figs. 9, 10 and 13, a first guide piece 64 that guides the fixed pin 58 in the front-rear direction is formed at the rear edge of the cutout 66. The first guide piece 64 is a plate member that hangs downward from the rear edge of the cutout 66. A first front-rear guide portion 62 that guides the fixed pin 58 in the front-rear direction is formed at the center of the first guide piece 64. The first front-rear guide portion 62 is perforated at the center of the first guide piece 64 (the center position in the vertical direction and the left-right direction of the first guide piece 64) so ​​as to penetrate the first guide piece 64 in the front-rear direction. The first front-rear guide portion 62 of this embodiment has a circular opening. The opening diameter of the first front-rear guide portion 62 is formed larger than the outer diameter of the fixed pin 58, and guides the fixed pin 58 to be movable in the front-rear direction.

[0062] As shown in Figs. 9, 10 and 13, the vertical through-hole 67 is formed in the middle of the intermediate support plate 83 in the front-rear direction. The vertical through-hole 67 is formed behind the notch 66 in the intermediate support plate 83, in the middle of the front-rear direction of the intermediate support plate 83, so as to penetrate the intermediate support plate 83 in the vertical direction. The vertical through-hole 67 in this embodiment is formed so that the opening width in the front-rear direction and the left-right direction is larger than the dimension (outer dimension) of the engagement member 51 in the front-rear direction and the left-right direction, and the upper end of the engagement member 51 can be guided (exposed) from below the intermediate support plate 83 to above it. In other words, the upper end of the engagement member 51 that engages with the fixing pin 58 can be exposed above the intermediate support plate 83 through the vertical through-hole 67.

[0063] As shown in Figures 9 and 10, a second guide piece 65 that guides the fixing pin 58 in the front-rear direction is formed on the front edge of the vertical through-hole 67. The second guide piece 65 is a plate member that hangs downward from the front edge of the vertical through-hole 67. The center of the second guide piece 65 (the middle position in the vertical direction and the left-right direction of the second guide piece 65) guides the fixing pin 58 in the front-rear direction. A second front and rear guide portion 63 is formed.

[0064] The second front-rear guide portion 63 is formed by drilling a hole at the center of the second guide piece 65 so as to penetrate the second guide piece 65 in the front-rear direction. In this embodiment, the second front-rear guide portion 63 has a circular opening. The opening diameter of the second front-rear guide portion 63 is formed larger than the outer diameter of the fixing pin 58, so that the fixing pin 58 can be freely guided in the front-rear direction.

[0065] The fixing pin 58 is inserted through both a first front-rear guide portion 62 and a second front-rear guide portion 63 that are arranged at a distance in the front-rear direction, so that the fixing pin 58 is guided linearly along the front-rear direction without wobbling.

[0066] As shown in Figures 10 and 13, the above-mentioned fixed pin 58 is provided with a rotation prevention mechanism 68 that prevents the disengagement lever 61 from rotating around the axis of the fixed pin 58 when the disengagement lever 61 is pulled.

[0067] If the disengagement lever 61 rotates around the axis of the fixed pin 58, the part that rotates with the fixed pin 58 may rub against other components such as the intermediate support plate 83, causing paint to peel off and leaving scratches that may mar the appearance. The rotation prevention mechanism 68 has the function of preventing this from occurring.

[0068] The rotation prevention mechanism 68 is fixed to the disengagement lever 61 and includes a rotating plate 69 that rotates integrally with the disengagement lever 61. The rotating plate 69 is attached to a fixed pin 58 located behind the disengagement lever 61.

[0069] The rotating plate 69 is a plate member attached to the fixed pin 58 behind the disengagement lever 61. The rotating plate 69 is fixed to the fixed pin 58 and is capable of rotating integrally with the fixed pin 58. The rotating plate 69 has a first portion 69a extending upward from below the cutout portion 66, and a second portion 69b extending rearward from the upper end of the first portion 69a.

[0070] The first portion 69a is a plate member disposed in an intersecting manner along the up-down direction with respect to the fixing pin 58 extending in the front-rear direction. The first portion 69a is fixed to the fixing pin 58 by welding or the like, and is rotatable integrally with the fixing pin 58.

[0071] The second portion 69b is a plate member extending in the front-rear direction and is provided so that its plate surface faces both up and down. The front end of the second portion 69b is connected to the upper end of the first portion 69a, and when the first portion 69a rotates, the second portion 69b can also rotate together with the first portion 69a around the axis of the fixing pin 58. The lower surface 70 of the second portion 69b is in surface contact with the upper surface 83a of the intermediate support plate 83.

[0072] An upper surface 83a of the intermediate support plate 83, which comes into surface contact with the lower surface 70 of the second portion 69b, serves as a rotation restricting portion that restricts the rotation of the rotating plate 69 by coming into surface contact with the rotating plate 69 (second portion 69b).

[0073] It is preferable that the lower surface 70 of the second portion 69b and the upper surface 83a of the intermediate support plate 83 are in surface contact with the driver's seat 6 at a position where they overlap in the vertical direction. If they are in surface contact with the driver's seat 6 at a position where they overlap in the vertical direction, the contact points (points where the rotating plate 69 and the intermediate support plate 83 come into contact) where scratches or the like are likely to appear are less visible from the outside. As a result, scratches or the like become less noticeable, and the appearance around the driver's seat 6 can be improved.

[0074] As shown in Fig. 11, the engaging member 51 is formed on the upper surface of the upper wall 101Ab (support plate) of the first cover body 101A so as to protrude upward. The engaging member 51 has a first plate portion 71 extending upward from the upper surface of the upper wall 101Ab (support plate) and a second plate portion 72 extending obliquely from the upper end of the first plate portion 71 toward the front and downward. In other words, the engaging member 51 has the first plate portion 71 and the second plate portion 72 connected in a bent state (mountain-shaped) at the upper end. In other words, the engaging member 51 is a member having a substantially inverted V shape. The connecting portion between the first plate portion 71 and the second plate portion 72 is formed in a curved shape.

[0075] 10, the angle α of the second plate portion 72 with respect to the upper surface of the upper wall 101Ab (support plate) is larger than the angle β of the first plate portion 71 with respect to the upper surface of the upper wall 101Ab (support plate). More specifically, the angle α is an obtuse angle, and the angle β is a right angle or a substantially right angle. The angle α can be set to, for example, 100° to 130°.

[0076] The engagement member 51 is fixed to the upper surface of the upper wall 101Ab (support plate). The plate portion 71 and the second plate portion 72 are fixed to the upper surface of the upper wall 101Ab (support plate). In this manner, both the first plate portion 71 and the second plate portion 72 are fixed to the upper surface of the upper wall 101Ab (support plate), whereby both ends of the generally inverted V-shaped engaging member 51 are fixed to the upper surface of the upper wall 101Ab (support plate). This improves the rigidity of the engaging member 51, and prevents the engaging member 51 from being deformed when the fixing pin 58 comes into contact with the engaging member 51.

[0077] The first plate portion 71 of the engaging member 51 is capable of restricting the fixed pin 58 from moving backward. In contrast, the second plate portion 72 of the engaging member 51 has an engaging hole 59 that allows the tip portion of the fixed pin 58 to be inserted in the front-rear direction. That is, the tip portion of the fixed pin 58 passes through the engaging hole 59 of the second plate portion 72 and engages with the engaging member 51 in a state of contacting the first plate portion 71. As a result, the fixed pin 58 is inserted through the engaging hole 59 of the second plate portion 72, and movement in the up-down direction is restricted. In addition, the fixed pin 58 is restricted from moving backward by contacting the first plate portion 71.

[0078] The tip of the fixed pin 58 is inserted into the engagement hole 59, whereby the fixed pin 58 is engaged with the engagement member 51. When the fixed pin 58 is engaged with the engagement member 51, the upward swing of the driver's seat 6 is restricted. That is, the engagement member 51 has an engagement hole 59 that restricts the upward swing of the driver's seat 6 by engaging with the tip of the fixed pin 58. In addition, the engagement member 51 restricts the fixed pin 58 from moving rearward from the position where the engagement member 51 is provided. That is, the engagement member 51 positions the rear end position of the fixed pin 58 at the installation position of the engagement member 51.

[0079] As shown in FIG. 11, the second plate portion 72 of this embodiment is a plate member that branches into two as it approaches the tip (lower end). In other words, the second plate portion 72 has a notch that is cut in a U-shape from the tip (lower end) upward. The tip (lower end) of the second plate portion 72 is fixed to the upper surface of the upper wall 101Ab (support plate), and this notch becomes the engagement hole 59. In other words, by forming such a notch in the second plate portion 72, the engagement hole 59 into which the tip of the fixing pin 58 can be inserted can be easily formed between the second plate portion 72 and the upper surface of the upper wall 101Ab by simply folding the second plate portion 72 downward relative to the first plate portion 71 and fixing the engagement member 51 to the upper surface of the upper wall 101Ab.

[0080] 10, the biasing member 60 is an elastic member attached to the fixing pin 58 at a midpoint in the front-rear direction. A spring member (coil spring) is used as the biasing member 60 in this embodiment. The biasing member 60 is disposed so as to be expandable and contractible in the front-rear direction.

[0081] The rear end of the urging member 60 is fixed to a spring attachment 73 attached to the fixed pin 58. The spring attachment 73 is attached to a midway portion of the fixed pin 58 in the front-rear direction. As a result, the rear end of the urging member 60 is fixed to the midway portion of the fixed pin 58 in the front-rear direction.

[0082] The front end of the urging member 60 is fixed to a first guide piece 64 that is provided in a hanging manner on the intermediate support plate 83. This allows the urging member 60 to generate a urging force in the front-rear direction while being sandwiched between the fixed pin 58 and the first guide piece 64 (intermediate support plate 83). Here, since the position of the first guide piece 64 is fixed, the urging force of the urging member 60 acts as a force that moves the fixed pin 58 rearward.

[0083] As shown in FIG. 10, the biasing member 60 has a neutral position where the biasing force is not generated in the forward or backward direction. That is, the coil spring constituting the biasing member 60 is in a natural length state where it is not expanded or contracted in the state shown in FIG. 9. The neutral position of the biasing member 60 in this embodiment is a position where the tip of the fixed pin 58 is inserted into the engagement hole 59 of the engagement member 51 (position where the engagement state RS is reached). Here, consider a case where the fixed pin 58 is pulled out forward from a state where the tip of the fixed pin 58 is engaged with the engagement hole 59 (engagement state RS). In this case, the position of the fixed pin 58 transitions to the front of the neutral position, and the coil spring constituting the biasing member 60 shortens from its natural length, so that a biasing force is generated in the fixed pin 58 in a direction to restore it to the rear (advancement direction). That is, the biasing member 60 applies a biasing force to the fixed pin 58 in a direction to restore it to the engagement state RS. As a result, when the driver's seat 6 is not swung upward, the fixing pin 58 is in a position (neutral position) where its tip is inserted into the engagement hole 59 of the engagement member 51, unless an external force (pulling force by the operator) is applied.

[0084] 10, a guide surface 74 is formed on the second plate portion 72 of the engagement member 51 to move the fixed pin 58 toward the retracted position P2 against the biasing force acting in a direction to restore the fixed pin 58 to the engaged state RS. In the case of this embodiment, the guide surface 74 is formed above the engagement hole 59 in the second plate portion 72 as an inclined surface that slopes upward and rearward. The tip of the fixed pin 58 comes into point contact or line contact with the guide surface 74.

[0085] Figure 12 shows specific examples in which the tip of the fixed pin 58 makes point contact or line contact with the guide surface 74. Figure 12(a) shows an example in which the tip of the fixed pin 58 makes line contact with the guide surface 74. Figure 12(b) shows an example in which the tip of the fixed pin 58 makes point contact with the guide surface 74.

[0086] 12(a), the guide surface 74 of the engagement member 51 is formed as a flat surface inclined toward the rear and upward. The inclination angle of the guide surface 74 with respect to the upper surface (upper wall 101Ab) of the seat support portion is set to θ1. The relationship between the angle θ1 and the above-mentioned angle α is θ1=180-α.

[0087] The tip of the fixing pin 58 has a chamfered portion 75. The chamfered portion 75 is formed by cutting the tip of the fixing pin 58. The chamfered portion 75 has a variety of configurations depending on the shape along which the tip of the fixing pin 58 is cut.

[0088] Chamfered portion 75 shown in Fig. 12(a) is formed by cutting the lower part of the tip of fixing pin 58 into a flat shape. That is, the tip of fixing pin 58 in Fig. 12(a) has a flat chamfered portion 75. The flat chamfered portion 75 in Fig. 12(a) is formed by cutting only the lower part of the tip into a flat shape, but the tip may also be cut into a conical or frustum shape to form a tapered chamfered portion 75.

[0089] As shown in FIG. 12(a), the flat chamfered portion 75 has an inclination angle (θ2) with respect to the upper surface of the seat support portion (upper wall 101Ab) when viewed along the axis of the fixed pin 58. Although not shown in FIG. 12(a), the tapered chamfered portion 75 also has the same inclination angle (θ2) at the lower end of the tip. The inclination angle (θ2) of the flat or tapered chamfered portion 75 changes with the swing of the driver's seat 6. That is, when the driver's seat 6 swings, the inclination angle of the fixed pin 58 changes. When the inclination angle of the fixed pin 58 changes, the inclination angle (θ2) of the chamfered portion 75 formed on the fixed pin 58 also changes with respect to the upper surface of the seat support portion (upper wall 101Ab).

[0090] In the cross-sectional view of FIG. 12(a), the tip of the chamfered portion 75 abuts against the second plate portion 72 of the engagement member 51 at one point on the surface at the upper part of the guide surface 74. When the driver's seat 6 swings from the "flip-up position S" to the "horizontal position H", the inclination angle (θ2) with respect to the upper surface (upper wall 101Ab) of the seat support part when viewed along the axis of the fixing pin 58 changes in a decreasing direction. At the same time as the change in the inclination angle (θ2), the position of the tip of the chamfered portion 75 moves forward, and the tip of the chamfered portion 75 moves so as to slide from the upper part to the lower part of the guide surface 74. As shown in FIG. 12(a), when the tip of the chamfered portion 75 is located at the upper part of the guide surface 74, the inclination angle (θ2) is clearly smaller than the inclination angle (θ1). Since the tilt angle (θ2) becomes smaller than the tilt angle (θ1) due to the swinging of the driver's seat 6, the tilt angle (θ2) does not coincide with the tilt angle (θ1) within the range in which the tip of the chamfered portion 75 slides from the top to the bottom of the guide surface 74 (the swing range of the fixed pin 58).

[0091] Taking FIG. 12(a) as a specific example, the inclination angle (θ1) is 45°, and the inclination angle (θ2) is smaller than 45° (before the fixed pin 58 is swung). When the fixed pin 58 is swung, the inclination angle (θ2) changes to an even smaller angle than the angle in FIG. 12(a). As long as the tip of the chamfered portion 75 contacts the guide surface 74, the inclination angle (θ2) does not become 0°. In other words, the inclination angle (θ2) changes in the range of 10°<θ2<45° within the swing range where the tip of the fixed pin 58 and the guide surface 74 abut, and the relationship (θ1)≠(θ2) always holds.

[0092] In this way, if the chamfered portion 75 is formed at an inclination angle (θ2) such that the relationship of "(θ1) ≠ (θ2)" holds between the inclination angle (θ1) and the chamfered portion 75, the tip of the chamfered portion 75 continues to contact the guide surface 74 even if the driver's seat 6 swings. 12(a), which shows the state, it appears to be in contact with guide surface 74 at a single point on the surface. However, in reality, the contact points continue in the left and right directions of the cross section, so guide surface 74 and chamfered portion 75 are in line contact with each other. This is because, when it is considered that guide surface 74 and chamfered portion 75 are contact between flat surfaces with different inclination angles, it can be easily understood that guide surface 74 and chamfered portion 75 are in line contact.

[0093] 12(a) is considered to show the state in which tapered chamfered portion 75 is in contact with guide surface 74, guide surface 74 and chamfered portion 75 are in point contact with each other because guide surface 74 and chamfered portion 75 are in contact with a curved surface and a flat surface. In this case, FIG. 12(a) can be considered to be a cross-sectional view taken along a cutting plane passing through the contact point between guide surface 74 and chamfered portion 75.

[0094] As shown in Fig. 12(b), the guide surface 74 of the engagement member 51 is formed as a flat surface inclined toward the rear and upward, similar to the case of Fig. 12(a). Fig. 12(b) differs from Fig. 12(a) in that the tip of the fixing pin 58 has a curved chamfered portion 75. That is, in the case of Fig. 12(b), the tip of the fixing pin 58 is rounded and formed into a hemispherical shape. The curved surface of the chamfered portion 75 also includes a curved surface that is approximately frustum-shaped or approximately conical.

[0095] Such curved chamfered portion 75 comes into point contact with planar guide surface 74 at a part of the curved surface (a part of chamfered portion 75). Which part of chamfered portion 75 comes into contact with guide surface 74 varies depending on the curvature of chamfered portion 75, the inclination angle (θ1) of guide surface 74, etc. Among the points on the curved surface of chamfered portion 75, curved chamfered portion 75 comes into point contact with planar guide surface 74 at a point where the angle of the tangent coincides with the inclination angle (θ1) of guide surface 74.

[0096] As shown in FIG. 12(a) and FIG. 12(b), when the tip of the fixing pin 58 is in point contact or line contact with the guide surface 74, the contact area is smaller than when the tip of the fixing pin 58 is in surface contact with the guide surface 74. As a result, the frictional force generated between the chamfered portion 75 and the guide surface 74 can be reduced, and the fixing pin 58 can be moved along the inclined guide surface 74 without hindrance. In other words, when the tip of the fixing pin 58 is moved along the guide surface 74, the movement is not hindered by the frictional force between the fixing pin 58 and the guide surface 74. This makes it easier to push the fixing pin 58 back in the exit direction by the guide surface 74. Therefore, the seat lock structure 50 can be changed from the disengaged state US to the engaged state RS by the weight of the driver's seat 6, and the driver's seat 6 can be reliably fixed to the aircraft (bonnet 14).

[0097] Next, we will explain the procedure for fixing the driver's seat 6 to the upper surface of the bonnet 14 using the seat lock structure 50 of this embodiment (in other words, a method for fixing the driver's seat 6 using the seat lock structure 50), and the procedure for releasing the driver's seat 6 (in other words, a method for releasing the driver's seat 6 using the seat lock structure 50).

[0098] In Fig. 15(a), the seat lock structure 50 is in the disengaged state US. As shown in Fig. 15(a), when the seat lock structure 50 of this embodiment is used to fix the driver's seat 6 to the upper surface of the bonnet 14, the intermediate support plate 83 and the rear part of the driver's seat 6 provided on the upper surface of the intermediate support plate 83 are swung downward. This swinging may be caused by the weight of the driver's seat 6, or may be caused by the force of the operator pushing down the driver's seat 6 in addition to the weight of the driver's seat 6. A support shaft 54c is provided at the front of the driver's seat 6, and the rear part of the driver's seat 6 swings downward around the support shaft 54c facing in the left-right direction.

[0099] When the rear part of the intermediate support plate 83 is swung downward around the support shaft 54c, the tip of the fixed pin 58 comes into contact with the upper part of the guide surface 74 of the engagement member 51. When the tip of the fixed pin 58 makes point contact with the guide surface 74, the frictional force generated between the tip of the fixed pin 58 and the guide surface 74 is smaller than in the case of surface contact. Therefore, the tip of the fixed pin 58 easily slides forward and downward along the inclined guide surface 74, and the fixed pin 58 moves forward against the biasing force of the biasing member 60.

[0100] In addition, when the tip of the fixed pin 58 is chamfered and the inclination angle (θ2) of the chamfered portion 75 is different from the inclination angle (θ1) of the guide surface 74, the chamfered portion 75 and the guide surface 74 come into line contact. Even in the case of line contact, the frictional force generated between the tip of the fixed pin 58 and the guide surface 74 is smaller than in the case of surface contact. Therefore, when the tip of the fixed pin 58 comes into line contact with the inclined guide surface 74, 4, and the fixing pin 58 moves forward against the biasing force of the biasing member 60.

[0101] 15(b), when the tip of the fixing pin 58 slides to the lower end of the inclined guide surface 74 and moves forward as the fixing pin 58 slides, the biasing member 60 is in the most shortened state. Therefore, the biasing member 60 generates the largest biasing force.

[0102] 15(c), when the tip of the fixed pin 58 slides below the inclined guide surface 74, the guide surface 74 for moving the fixed pin 58 forward no longer exists. In other words, the tip of the fixed pin 58 reaches the engagement hole 59. Therefore, the movement direction of the fixed pin 58 is changed by the action of the biasing force generated in the biasing member 60. As a result, the fixed pin 58 moves from the retracted position P2 to the advanced position P1 through the engagement hole 59.

[0103] 15(d), the tip of the fixing pin 58 that has moved to the advanced position P1 is inserted into the engagement hole 59, and the fixing pin 58 engages with the engagement hole 59 of the engagement member 51. As a result, the intermediate support plate 83 on which the fixing pin 58 is provided and the driver's seat 6 supported by the intermediate support plate 83 are fixed to the upper wall 101Ab on which the engagement member 51 is provided. In this manner, the seat lock structure 50 switches from the disengaged state US to the engaged state RS.

[0104] In Fig. 16(a), the seat lock structure 50 is in the engaged state RS, and the fixing pin 58 is in a position slightly moved forward from the advanced position P1. As shown in Fig. 16(a), when the driver's seat 6 is released from the locked position by using the seat lock structure 50 of this embodiment, the operator pulls the disengagement lever 61 forward from the state shown in Fig. 15(d), and the pulling operation of the disengagement lever 61 moves the fixing pin 58 connected to the disengagement lever 61 from the advanced position P1 to the retracted position P2.

[0105] 16(b), when the fixing pin 58 moves to the retracted position P2, the tip of the fixing pin 58 comes out of the engagement hole 59. As a result, the driver's seat 6 is released from its fixed position.

[0106] 16(c), when the driver's seat 6 and the rear part of the intermediate support plate 83 are swung upward with the tip of the fixed pin 58 out of the engagement hole 59, the tip of the fixed pin 58 that has come out of the engagement hole 59 comes into contact with the guide surface 74 adjacent to the upper part of the engagement hole 59. The guide surface 74 is inclined toward the upper rear, and the tip of the fixed pin 58 is in point contact or line contact with the guide surface 74. Therefore, the biasing force of the biasing member 60 causes the tip of the fixed pin 58 to move on the guide surface 74 along the inclination direction of the guide surface 74 (toward the upper rear).

[0107] 16(d), when the rear part of the driver's seat 6 is further swung upward from the state where the tip of the fixing pin 58 is positioned above the guide surface 74, the fixing pin 58 moves rearward until the biasing member 60 returns to its natural length. In this way, the seat lock structure 50 switches from the engaged state RS to the disengaged state US.

[0108] The seat lock structure 50 of the present invention is a seat lock structure that fixes a driver's seat 6, which is arranged to be able to swing freely around a horizontal axis relative to a seat support part (upper wall 101Ab), in a state in which swinging relative to the seat support part is restricted, and includes a fixing pin 58 that is arranged on a bottom surface 6C of the driver's seat 6 and moves between two points, an advanced position P1 and a retracted position P2, an engagement member 51 that is arranged on an upper surface of the seat support part and engages with the fixing pin 58 at the advanced position P1, and an urging force that urges the fixing pin 58 in a direction to move to the advanced position P1. The engaging member 51 has an engaging hole 59 into which the fixed pin 58 is inserted when the fixed pin 58 is in the advanced position P1 to restrict the upward swing of the driver's seat 6, and an inclined guide surface 74 which comes into contact with the tip of the fixed pin 58 in the advanced position P1 when the driver's seat 6 is swung downward, and guides the tip to the engaging hole 59 while moving the fixed pin 58 in the direction of the exit position P2 against the biasing force as the driver's seat 6 swings downward, and the tip of the fixed pin 58 makes point contact or line contact with the guide surface 74.

[0109] According to the above-mentioned configuration, the tip of the fixing pin 58 is in point contact or line contact with the guide surface 74, so that the frictional force generated between the tip and the guide surface 74 is small. Therefore, the tip of the fixing pin 58 that contacts the guide surface 74 easily moves along the guide surface 74 and is guided to the engagement hole 59. Therefore, in the seat lock structure 50 of the present invention, the driver's seat 6 can be easily fixed to the aircraft body 2. Also, the engagement member 51 is provided on the seat support portion side, and the fixing Since the fixing pin 58 is provided on the driver's seat 6 side, the engaging member 51 can be prevented from coming into contact with other members and becoming deformed, as compared to when the engaging member 51 is provided on the driver's seat 6 side.

[0110] The seat lock structure 50 includes a support plate (upper wall 101Ab) arranged below the engaging member 51, and the engaging member 51 includes a first plate portion 71 extending upward from the upper surface of the support plate, and a second plate portion 72 extending forward and downward from the upper end of the first plate portion 71 and having a guide surface 74 and an engaging hole 59, and the first plate portion 71 and the second plate portion 72 are fixed to the upper surface of the support plate.

[0111] With this, by fixing both the first plate portion 71 and the second plate portion 72 to the upper surface of the support plate (upper wall 101Ab), the rigidity of the engaging member 51 is improved, and deformation of the engaging member 51 can be prevented when the fixing pin 58 comes into contact with the engaging member 51.

[0112] Of the two members provided on the engagement member 51, the second plate portion 72 is located in front of the first plate portion 71 (at a position close to the retreat position P2). Therefore, when the fixing pin 58 is moved horizontally toward the advance position P1 (rearward), the tip of the fixing pin 58 is first inserted into the engagement hole 59 of the second plate portion 72. When the fixing pin 58 is moved further rearward, the tip of the fixing pin 58 comes into contact with the first plate portion 71. Unlike the second plate portion 72, the first plate portion 71 does not have the engagement hole 59, and the forward movement of the fixing pin 58 is restricted by the first plate portion 71. In other words, the above-mentioned engagement member 51 has both a function of fixing the fixing pin 58 to the upper wall 101Ab (upper surface of the support plate) by engaging with the engagement hole 59 so as not to swing up and down, and a function of restricting the forward movement of the fixing pin 58 by contacting the first plate portion 71 (a function of positioning the tip of the fixing pin 58 at a position where it comes into contact with the first plate portion 71).

[0113] The tip of the fixing pin 58 has a flat or tapered chamfered portion 75, and the inclination angle (θ1) of the guide surface 74 relative to the upper surface of the seat support portion (upper wall 101Ab) and the inclination angle (θ2) of the chamfered portion 75 relative to the upper surface of the seat support portion when viewed along the horizontal axis are different from each other within the swing range where the tip of the fixing pin 58 and the guide surface 74 abut as the driver's seat 6 sways, and the tip of the chamfered portion 75 abuts against the guide surface 74.

[0114] According to this, the contact surface 75 provided at the tip of the fixing pin 58 makes line contact or point contact with the guide surface 74 of the engaging member 51, so that the frictional force is smaller than when the surfaces contact each other. This makes it easier for the tip of the fixing pin 58 to move along the guide surface 74. As a result, when the tip of the fixing pin 58 makes contact with the guide surface 74, it becomes easier to move the fixing pin 58 to the advanced position P1, and the engagement of the seat lock structure 50 can be performed smoothly and easily.

[0115] The tip of the fixing pin 58 has a curved chamfered portion, and a part of the chamfered portion may be in point contact with the guide surface 74 .

[0116] According to this, the tip of the fixing pin 58, which is formed into a curved surface, comes into point contact with the guide surface 74 of the engaging member 51. Such point contact has even smaller frictional force than when surfaces contact each other or when there is line contact. This makes it easier for the tip of the fixing pin 58 to move along the guide surface 74. As a result, when the tip of the fixing pin 58 comes into contact with the guide surface 74, it becomes easier to move the fixing pin 58 to the advanced position P1, and the engagement of the seat lock structure 50 can be performed smoothly and easily.

[0117] The seat lock structure 50 includes a disengagement lever 61 connected to the fixed pin 58 and configured to move the fixed pin 58 from an advanced position P1 to a retracted position P2 by a pulling operation, and a rotation prevention mechanism 68 that prevents the disengagement lever 61 from rotating around the axis of the fixed pin 58 during the pulling operation.

[0118] According to this, an operator can grasp and pull the disengagement lever 61 to move the fixed pin 58 from the advanced position P1 to the retracted position P2 against the biasing force of the biasing member 60. Also, when the disengagement lever 61 is grasped, the disengagement lever 61 can be prevented from rotating about the axis of the fixed pin 58. If the disengagement lever 61 rotates about the axis of the fixed pin 58, the part that rotates together with the fixed pin 58 may rub against other members such as the intermediate support plate 83, leaving scratches due to peeling paint, which may cause a defect that mars the appearance; however, the rotation prevention mechanism 68 can prevent this defect from occurring.

[0119] The anti-rotation mechanism 68 has a rotating plate 69 fixed to the disengagement lever 61 and rotating integrally with the disengagement lever 61, and a rotation restriction portion that restricts the rotation of the rotating plate 69 by making surface contact with the rotating plate 69.

[0120] By employing such a rotation prevention mechanism 68, the rotating plate 69, which is fixed to the disengagement lever 61 and rotates integrally therewith, comes into surface contact with the rotation restriction portion, thereby reliably restricting the rotation of the rotating plate 69. In other words, by using the above-described rotation prevention mechanism 68, the rotation of the disengagement lever 61 can be easily and reliably restricted.

[0121] An intermediate support plate 83 is disposed below the driver's seat 6 at a position spaced downward from the bottom surface of the driver's seat 6, and the intermediate support plate 83 is formed with a rotation restriction portion.

[0122] According to this, by bringing the upper surface 83a of the intermediate support plate into surface contact with the lower surface 70 of the second portion 69b, the rotation of the rotating plate 69 and the disengagement lever 61 can be more simply and reliably suppressed.

[0123] The upper end of the pivot plate 69 protrudes above the intermediate support plate 83, and the pivot control portion is composed of a notch 66 cut out from the front end of the intermediate support plate 83 toward the rear, and the pivot plate 69 has a first portion 69a extending upward from below the notch 66 and a second portion 69b extending rearward from the upper end of the first portion 69a, and the lower surface of the second portion 69b is in surface contact with the upper surface 83a of the intermediate support plate 83.

[0124] By forming the notch 66 at the front end of the intermediate support plate 83 in this manner, the notch 66 can be used to restrict the rotation of the rotating plate 69. In other words, if the rotating plate 69 includes a first portion 69a extending upward from below the notch 66 and a second portion 69b extending rearward from the upper end of the first portion 69a, the opening edge of the notch 66 and both left and right ends of the first portion 69a come into contact with each other, thereby first restricting the rotation of the rotating plate 69. In addition, the lower surface of the second portion 69b comes into surface contact with the upper surface 83a of the intermediate support plate 83, thereby restricting the rotation of the rotating plate 69. This makes it possible to more reliably restrict the rotation of the rotating plate 69.

[0125] The lower surface 70 of the second portion 69b and an upper surface 83a of the intermediate support plate 83 are in surface contact with the driver's seat 6 at a position where they overlap in the up-down direction.

[0126] In this way, if the underside 70 of the second portion 69b and the upper side 83a of the intermediate support plate 83 are in surface contact at a position overlapping with the driver's seat 6 in the up-down direction, the contact point where the underside 70 of the second portion 69b and the upper side 83a of the intermediate support plate 83 are in surface contact becomes difficult to see from the outside. Since the contact point is prone to produce scratches, etc., if the scratches, etc. become difficult to see from the outside, it becomes easier to maintain a good appearance around the driver's seat 6.

[0127] The fixing pin 58 is attached to the lower part of the intermediate support plate 83, and the intermediate support plate 83 has an upper and lower through-hole 67 formed therein, which exposes the upper end of the engaging member 51, which engages with the fixing pin 58, toward the upper side of the intermediate support plate 83.

[0128] According to this, the upper end of the engaging member 51 can be exposed upward from the vertical through-hole 67, so even if the position (installation height) of the intermediate support plate 83 is brought closer to the support plate (upper wall 101Ab), the upper end of the engaging member 51 will not come into contact with the intermediate support plate 83. Therefore, a sufficient height of the engaging member 51 can be ensured regardless of the position (installation height) of the intermediate support plate 83. In other words, since a sufficient vertical dimension can be ensured for the engaging hole 59 and the guide surface 74 of the engaging member 51, it is possible to reliably fix and release the fixing pin 58.

[0129] The working machine 1 of the present invention includes an operator's seat 6 in which an operator sits, a seat support portion (upper wall 101Ab) that supports the operator's seat 6, and the seat lock structure 50 described above.

[0130] With such a work machine 1, the operator's seat 6 can be easily fixed to the seat support portion in a state in which its rocking motion is restricted.

[0131] Although the embodiment of the present invention has been described above, the embodiment disclosed herein should be considered as illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0132] 1 Work equipment 6 Driver's seat 6C Bottom 14 Bonnet 50 Sheet Rock Structure 51 Engagement member 58 Fixing pin 59 Engagement hole 60 biasing member 61 Disengagement lever 66 Notch 67 Upper and lower penetration parts 68 Anti-rotation mechanism 69 Rotating plate 69a Part 1 69b Part 2 70 Bottom surface 71 1st plate part 72 2nd plate part 74 Guide Surface 75 Chamfer 83 Intermediate support plate 83a top surface 91 Prime Mover 101Ab Upper wall (support plate, sheet support part) P1 advance position P2 exit position

Claims

1. A seat lock structure that fixes a driver's seat that is arranged to be freely pivotable about a horizontal axis relative to a seat support part in a state in which the pivoting of the driver's seat relative to the seat support part is restricted, A fixed pin is provided on the bottom surface of the driver's seat and moves between an advanced position and an exit position; an engagement member disposed on an upper surface of the seat support portion and engaging with the fixing pin at the advanced position; a biasing member that applies a biasing force to the fixing pin in a direction in which the fixing pin is moved to the advanced position; Equipped with The engaging member is an engagement hole into which the fixing pin is inserted when the fixing pin is in the advanced position to restrict upward pivoting of the driver's seat; an inclined guide surface that comes into contact with a tip end of the fixing pin in the advanced position when the driver's seat is swung downward, and that guides the tip end to the engagement hole while moving the fixing pin toward the retreated position against the biasing force as the driver's seat is swung downward; It has A seat lock structure in which the tip of the fixing pin makes point contact or line contact with the guide surface.

2. A support plate is provided below the engagement member, The engaging member is a first plate portion extending upward from an upper surface of the support plate, and a second plate portion extending forward and downward from an upper end of the first plate portion and having the guide surface and the engagement hole, The seat lock structure according to claim 1 , wherein the first plate portion and the second plate portion are fixed to an upper surface of the support plate.

3. The tip has a flat or tapered chamfer, The inclination angle (θ 1 ) and the inclination angle (θ 2 2. The seat lock structure according to claim 1, wherein the chamfered portion and the guide surface are different from each other within a pivot range in which the tip portion and the guide surface abut as the driver's seat pivots, and the tip of the chamfered portion abuts against the guide surface.

4. The seat lock structure according to claim 1 , wherein the tip portion has a curved chamfered portion, and a part of the chamfered portion comes into point contact with the guide surface.

5. a disengagement lever connected to the fixing pin and configured to move the fixing pin from the advanced position to the retracted position by a pulling operation; a rotation prevention mechanism that prevents the disengagement lever from rotating around the axis of the fixing pin during the pulling operation; The seat rock structure according to claim 1 ,

6. The rotation prevention mechanism includes: a rotating plate fixed to the disengagement lever and rotating integrally with the disengagement lever; The seat lock structure according to claim 5 , further comprising a rotation restricting portion that restricts rotation of the rotating plate by coming into surface contact with the rotating plate.

7. An intermediate support plate is provided below the driver's seat at a position spaced downward from a bottom surface of the driver's seat, The seat lock structure according to claim 6 , wherein the rotation restricting portion is formed on the intermediate support plate.

8. The upper end of the rotating plate protrudes above the intermediate support plate, the rotation restriction portion is formed of a notch portion that is cut rearward from a front end of the intermediate support plate, The rotating plate has a first portion extending upward from below the notch portion and a second portion extending rearward from an upper end of the first portion, The seat lock structure according to claim 7 , wherein a lower surface of the second portion is in surface contact with an upper surface of the intermediate support plate.

9. The seat lock structure according to claim 8 , wherein a lower surface of the second portion and an upper surface of the intermediate support plate are in surface contact with each other at a position where the lower surface and the upper surface of the intermediate support plate overlap with the driver's seat in the vertical direction.

10. The fixing pin is attached to a lower portion of the intermediate support plate, The seat lock structure according to claim 7 , wherein the intermediate support plate is formed with a vertical through-hole for exposing an upper end of the engagement member that engages with the fixing pin toward above the intermediate support plate.

11. A driver's seat in which an operator sits; A seat support portion that supports the driver's seat; The seat lock structure according to any one of claims 1 to 10, which fixes the driver's seat in a state in which the driver's seat is restricted from rocking relative to the seat support portion; A work machine equipped with the above.

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