Work vehicles

Abstract

The objective is to provide a work vehicle that can ensure safety when raising and lowering work equipment outside the work vehicle. [Solution] In a work vehicle in which a work machine 9 is mounted on the rear of the machine body so as to be able to be raised and lowered via a connecting means 8, work machine lifting and lowering operating devices 24 and 25 for raising and lowering the work machine 9 are provided near the cockpit 12, and an external manual operating device 51 for raising and lowering the work machine 9 is provided on the outside of the machine body, a first person detection sensor 52 capable of detecting the presence of a person near the position where the external manual operating device 51 is operated is provided, and when the first person detection sensor 52 detects the presence of a person, the operation of the work machine lifting and lowering by the work machine lifting and lowering operating devices 24 and 25 is restricted. In addition, a second person detection sensor 53 capable of detecting the presence of a person between the machine body and the work machine 9 at the rear of the machine body is provided, and the operation of the external manual operating device 51 is enabled when the first person detection sensor 52 detects a person and the second person detection sensor 53 does not detect a person.

Description

【Technical Field】 【0001】 The present invention relates to a work vehicle such as an agricultural tractor. 【Background Art】 【0002】 There is a known work vehicle in which a first switch for raising a working implement and a second switch for lowering the working implement are provided at the rear of a fender, so that the raising and lowering operation of the working implement can be performed from outside the vehicle (Patent Document 1). 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2001-10362 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 According to Patent Document 1, the raising and lowering operation can be performed while checking the working implement in the vicinity thereof. However, there is a possibility that the operator may be pinched by the working implement due to an unexpected operation and injured. 【0005】 An object of the present invention is to provide a work vehicle capable of ensuring safety during the raising and lowering operation of a working implement outside the work vehicle. 【Means for Solving the Problems】 【0006】 In order to solve the above problems and achieve the object, the invention according to claim 1 mounts a working implement 9 on the rear of the vehicle body so as to be able to be raised and lowered via a connecting means 8, and provides working implement raising and lowering operation tools 24, 25 for raising and lowering the working implement 9 in the vicinity of the driver's seat 12, and provides an external manual operation tool 5 for raising and lowering the working implement 9 outside the vehicle body. In the work vehicle provided with 1, a first person detection sensor 52 capable of detecting the presence of a person in the vicinity of the position where the external manual operation tool 51 is operated is provided, and when the first person detection sensor 52 detects the presence of a person, the working implement raising and lowering operation by the working implement raising and lowering operation tools 24, 25 is restricted. 【0007】 The invention described in claim 2 is the invention described in claim 1, further comprising a second person detection sensor 53 capable of detecting the presence of a person between the machine body and the work machine 9 at the rear of the machine body, and enabling the operation of the external manual operating device 51 when the first person detection sensor 52 detects a person and the second person detection sensor 53 does not detect a person. 【0008】 The invention described in claim 3 is the invention described in claim 2, wherein the operation of the external manual operating device 51 is made effective when the parking brake of the machine is engaged and the PTO is not driven. [Effects of the Invention] 【0009】 According to the invention described in claim 1, if the presence of a person is detected near the position where the external manual operating tool 51 is operated, the raising and lowering operation of the work machine 9 from the cockpit 11 is restricted, thereby preventing unnecessary raising and lowering of the work machine for workers outside the machine and ensuring safety. 【0010】 According to the invention described in claim 2, when operating the external manual operating tool 51, the first person detection sensor 52 restricts the raising and lowering operation of the work machine at the control unit 12, thereby ensuring safe operation near the position where the external manual operating tool 51 is operated. The second person detection sensor 53 detects the absence of a person, allowing the raising and lowering of the work machine 9 to be permitted, thus avoiding dangers such as pinching. 【0011】 According to the invention described in claim 3, in addition to the effects described in claim 2, it is possible to prevent the machine from moving unexpectedly or the parts of the work implement 9 from rotating unexpectedly, and to safely perform the lifting and lowering operation of the work implement. [Brief explanation of the drawing] 【0012】 [Figure 1] This is an overall side view of a tractor body according to an embodiment of the present invention. [Figure 2] This is a perspective view of the main parts of the cockpit. [Figure 3] This is an overall plan view of the tractor machine. [Figure 4] This is a flowchart. [Modes for carrying out the invention] 【0013】 An agricultural tractor will be described as an example of a work vehicle to which the present invention applies. 【0014】 Tractor 1 consists of a body with two front wheels (2, 2) and three rear wheels (3, 3), a cabin (4) covering the control section, and an engine (6) mounted in a bonnet (5) at the front of the body. The rotational power of this engine (6) is transmitted to a variable-speed transmission unit (7a) in a transmission case (7), and the power, which is appropriately reduced by this variable-speed transmission unit (7a), is transmitted to the two front wheels (2, 2) and the three rear wheels (3, 3). At the same time, the engine is configured to output driving force to an implement (9) connected to the rear of the body via a 3P link (8) as a connecting means, through a PTO output shaft (10'). Specifically, the rear of the body is provided with a 3P link (8), which consists of an upper top link (8a) and lower left and right links (8b), to which the implement (9) is connected. The implement (9) is a tilling implement and includes tilling tines (9a) for tilling the soil of the field, a rotary cover (9b) covering the top of the tilling tines (9a), and a rear cover (9c) that is supported at the rear of the rotary cover (9b) so as to be able to move up and down. 【0015】 A work equipment lifting cylinder 11' is connected to the lower link 8b of the 3P link 8 via a lift arm 10, and the lower link 8b can be raised and lowered by supplying and discharging pressurized oil to the work equipment lifting cylinder 11'. 【0016】 As shown in the perspective view of Figure 2, the cockpit 12 is positioned above the transmission case 7 inside the cabin 4. An armrest 13 is provided on one side of the cockpit 12, and a control panel device 14 (described later) is located to its outside. On the other side of the cockpit 12, a parking brake lever 15 and a PTO change lever 16 are positioned to form the control section. A forward / reverse lever 18 is located near the steering wheel 17, and a clutch pedal 19, left and right brake pedals 20L and 20R, and an accelerator pedal 21 are located near the footpegs. A meter panel 23 displaying instrument information, including a speedometer, is provided on the steering post. In front of the armrest 13, a work implement lifting lever 24 and work implement lifting switch 25 are located, as well as an accelerator lever 26 and a main transmission speed increase / decrease switch 27. When the work implement lifting lever 24 is tilted forward, the work implement 9 is lowered, and when it is tilted backward, the work implement 9 is raised. Furthermore, the implement lifting lever 24 also functions as a position control lever, allowing the height of the implement 9 in the lowered position to be set by adjusting its forward tilt angle. Additionally, tilting the accelerator lever 26 forward increases the engine speed, while tilting it backward decreases it. 【0017】 The control panel device 14 consists of a front panel section 14A at the front, a rear panel section 14B at the rear, and an upper panel section 14C on the window side. The front panel section 14A is equipped with a sub-speed lever 30 for switching the sub-speed between high and low speeds. The sub-speed lever 30 is also equipped with a main speed increase switch 31a and a main speed decrease switch 31b, allowing the main speed to be increased or decreased by operating the switches. Behind the sub-speed lever 30 are a constant speed switch 32 and a PTO switch 33 for turning the drive of the PTO shaft (not shown) ON and OFF. 【0018】 The rear panel section 14B is configured as an inclined surface and includes a rotation speed increase / decrease switch 34, a brake adjustment dial 35, and the like. The rotation speed increase / decrease switch 34 adjusts the memory accelerator rotation speed in the memory function that maintains the set accelerator rotation speed state. The brake adjustment dial 35 adjusts the braking force of the automatic brake during turns to a stronger or weaker setting. 【0019】 A plurality of external hydraulic levers 36, 36 are provided on the outer panel portion 14C. 【0020】 Next, an external manual operation tool provided on the fender 50 outside the machine body will be described. 【0021】 As shown in FIG. 1, the left and right fenders 50 are curved so as to cover the upper part of the rear wheels. An external manual switch 51 for raising and lowering a 3P link, which is an external manual operation tool, is arranged on the rear side surface of one 50L of the fenders 50. This external manual switch 51 is composed of a raise switch 51U for raising the working machine and a lower switch 51D for lowering the working machine. And a first human detection sensor 52 is arranged at substantially the same position as this external manual switch 51. This first human detection sensor 52 is, for example, an infrared sensor and is configured to be able to detect the presence of a person in the vicinity outside the fender 50L (FIG. 3). 【0022】 In addition, a second human detection sensor 53 is provided on the rear side of the left fender 50L, and the second human detection sensor 53 can detect the presence of a person between the rear part of the machine body and the working machine 9 (the same figure). The second human detection sensor 53 is provided as left and right sensors 53L, 53R corresponding to the left and right fenders 50L, 50R as shown in the figure. 【0023】 The 3P link lifting output control using the external manual switch 51 will be explained with reference to Figure 4. When the first person detection sensor 52 detects the presence of a person near the fender 50L (S101), when there is no operation of the work equipment lifting lever 21 or the PTO lifting operation using the work equipment lifting switch 22 in the cockpit 11 (S102, S103), and when the second person detection sensor 53 does not detect the presence of a person between the rear of the machine and the work equipment 9 (S104), the up or down operation of the external manual switch 51 is activated (S105). That is, when the up switch 51U of the external manual switch 51 is turned ON, the 3P link is raised (S106), and when the down switch 51D is operated, the 3P link is lowered (S107). The work equipment 9 can be raised or lowered while visually checking its status by operating the switch near the fender 50L. In addition, if neither the up switch 51U nor the down switch 51D is operated in S105, neither the up nor down output will be displayed (S108). 【0024】 Even if the aforementioned work equipment lifting lever 21 or work equipment lifting switch 22 is operated, either the 3P link raising or lowering output is restricted (S109). With this configuration, if the presence of a person is detected near the fender 50L, the lifting operation of the work equipment 9 from the cockpit 11 is restricted, thereby preventing unnecessary lifting and lowering of the work equipment for workers outside the machine, ensuring safety. 【0025】 The up switch 51U and down switch 51D, which serve as external manual switches 51, are configured to maintain an ON output while pressed and to output an OFF output when released. 【0026】 As described above, when operating the external manual switch 51, the first person detection sensor 52 restricts the lifting and lowering operation of the work equipment at the control unit 12, thereby ensuring safety near the fender 50L. The second person detection sensor 53 detects the absence of a person, enabling the lifting and lowering of the work equipment 9, thus avoiding dangers such as pinching. 【0027】 Next, further conditions associated with the operation of the external manual switch 51 will be described. Specifically, the lifting and lowering output of the work implement based on the operation of the external manual switch 51 is enabled when the parking brake is activated by operating the parking brake lever 15, and when the PTO is not driven, with the PTO change lever 16 in the neutral position and the PTO switch 33 OFF, so that no driving force is transmitted to the PTO output shaft. With this configuration, it is possible to prevent the machine from moving unexpectedly or the parts of the work implement 9 from rotating unexpectedly, and to perform the lifting and lowering operation of the work implement safely. [Explanation of Symbols] 【0028】 8. 3P link (connecting means) 9. Work equipment 12 cockpits 24. Work equipment lifting lever (work equipment lifting control device) 25. Work equipment lifting switch (work equipment lifting control device) 51 External manual switch (external manual operating device) 52. First Human Detection Sensor 53. Second Human Detection Sensor

Claims

[Claim 1] A work vehicle is provided in which a work machine (9) is mounted on the rear of the machine body so as to be able to be raised and lowered via a connecting means (8), work machine lifting and lowering operating devices (24, 25) for raising and lowering the work machine (9) are provided near the cockpit (12), and an external manual operating device (51) for raising and lowering the work machine (9) is provided outside the machine body, wherein a first person detection sensor (52) capable of detecting the presence of a person near the position where the external manual operating device (51) is operated is provided, and when the first person detection sensor (52) detects the presence of a person, the lifting and lowering operation of the work machine by the work machine lifting and lowering operating devices (24, 25) is restricted. [Claim 2] A work vehicle according to claim 1, comprising a second person detection sensor (53) capable of detecting the presence of a person between the machine body and the work machine (9) at the rear of the machine body, wherein the operation of the external manual operating device (51) is enabled when the first person detection sensor (52) detects a person and the second person detection sensor (53) does not detect a person. [Claim 3] The work vehicle according to claim 2, wherein the operation of the external manual control device (51) is effective when the machine's parking brake is engaged and the PTO is not driven.

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