Inverter unit and work vehicle

Abstract

In the inverter unit, the aim is to reduce space by optimizing the arrangement of multiple inverter circuits. [Solution] The system includes a battery connector 4, output connectors 5, 6, and 7, and a circuit board member 3. Multiple inverter circuits 11, 12, and 13, each connected to one of the multiple output connectors 5, 6, and 7, are mounted on the circuit board member 3. Distribution circuits 15 and 16, which supply power supplied to the battery connector 4 to each of the multiple inverter circuits 11, 12, and 13, are mounted on the circuit board member 3. Multiple fuses 18, provided in the parts of the distribution circuits 15 and 16 corresponding to the multiple inverter circuits 11, 12, and 13, are mounted on the circuit board member 3.

Description

Technical Field

[0001] The present invention relates to a configuration of an inverter unit and a work vehicle equipped with the inverter unit.

Background Art

[0002] In the work vehicle disclosed in Patent Document 1, a plurality of electric motors such as an electric motor for traveling and an electric motor for driving a work device are provided, and a plurality of inverter circuits (motor controllers) are provided for each of the plurality of electric motors. Power of a battery is supplied to each of the plurality of inverter circuits, and power is supplied from the inverter circuits to each of the plurality of electric motors.

[0003] In this case, each inverter circuit is configured as one independent unit by each substrate member and case, and the units of the plurality of inverter circuits may be mounted on the work vehicle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, when units of a plurality of inverter circuits are mounted on a work vehicle, a harness is connected to each of the units of the plurality of inverter circuits. Thereby, when arranging the units of the plurality of inverter circuits, a relatively large space is required for arranging a large number of harnesses, so there is room for improvement.

[0006] The present invention aims to reduce the space required for arranging multiple inverter circuits in an inverter unit, and to provide a work vehicle in which multiple inverter circuits are provided in a space-saving manner. [Means for solving the problem]

[0007] The inverter unit of the present invention comprises a battery connector that can be connected to a battery, a plurality of output connectors that can be connected to each of a plurality of electric motors, a circuit board member, a plurality of inverter circuits mounted on the circuit board member and connected to each of the plurality of output connectors, a distribution circuit mounted on the circuit board member that supplies power supplied to the battery connector to each of the plurality of inverter circuits, and a plurality of fuses mounted on the circuit board member and provided in the portion of the distribution circuit corresponding to the plurality of inverter circuits.

[0008] According to the present invention, power supplied to the battery connector is supplied to each of the multiple inverter circuits via a distribution circuit. Multiple fuses are provided in the portion of the distribution circuit corresponding to the multiple inverter circuits. Power from the inverter circuits is supplied to each of the multiple electric motors from multiple output connectors.

[0009] According to the present invention, multiple inverter circuits are mounted on a common circuit board, and a distribution circuit and multiple fuses are mounted on the same circuit board. By mounting multiple inverter circuits, distribution circuits, and fuses on the same circuit board, the multiple inverter circuits, distribution circuits, and fuses can be compactly configured, thus enabling the creation of a compact inverter unit equipped with multiple inverter circuits. The compact inverter unit allows for space savings in the arrangement of multiple inverter circuits.

[0010] According to the present invention, a distribution circuit that supplies power supplied to a battery connector to each of a plurality of inverter circuits, and a plurality of fuses are mounted on the same circuit board, thereby reducing the number of components by commonizing wiring and the like. By reducing the number of parts, the assembly time for the inverter unit can be reduced, and the inverter unit can be made lighter.

[0011] In the present invention, it is preferable that the battery connector and the output connector are attached to a case that houses the circuit board member, the inverter circuit, the distribution circuit, and the fuse.

[0012] According to the present invention, the circuit board, inverter circuit, distribution circuit, and fuse are housed in a single case, and the battery connector and output connector are attached to the case, thus making the case more compact. The ability to make the case more compact offers an advantage in that it allows for the creation of a more compact inverter unit.

[0013] In the present invention, it is preferable that a heat sink is provided that is attached across multiple inverter circuits.

[0014] According to the present invention, by attaching the heat sink across multiple inverter circuits, a relatively large heat sink is obtained, resulting in a heat sink with a relatively large surface area. This promotes heat dissipation from the inverter circuits, thereby improving the durability of the inverter circuits.

[0015] According to the present invention, for example, if one inverter circuit generates a large amount of heat while another inverter circuit generates little heat, it can be expected that the heat from the inverter circuit generating a large amount of heat will be transferred to the part of the heat sink corresponding to the inverter circuit generating little heat, and dissipated. This allows the heat generated by the inverter circuit with the highest heat output to be dissipated smoothly, even if there are differences in the amount of heat generated in multiple inverter circuits, thereby improving the durability of the inverter circuits.

[0016] In the present invention, it is preferable that the distribution circuit is attached to a first surface on one side of the substrate member, the inverter circuit is attached to a second surface on the substrate member opposite to the first surface, and the heat sink is positioned on the side of the second surface and attached across a plurality of inverter circuits.

[0017] According to the present invention, the distribution circuit is mounted on the first surface of the substrate member, and the inverter circuit is mounted on the second surface of the substrate member, so that the distribution circuit and the inverter circuit are located on opposite sides of the substrate member. This makes the distribution circuit less susceptible to the heat generated by the inverter circuit, thus improving the durability of the distribution circuit and offering advantages in terms of improving the durability of the inverter unit.

[0018] According to the present invention, the inverter circuit is attached to the second surface of the substrate member, and the heat sink is positioned on the side of the second surface, making it easy to position the heat sink close to the inverter circuit. This allows for rapid heat transfer from the inverter circuit to the heatsink, promoting heat dissipation from the inverter circuit and offering advantages in terms of improving the inverter circuit's durability. If the heatsink can be easily positioned close to the inverter circuit, it becomes easier to attach the heatsink to the inverter circuit, thus simplifying the heatsink's mounting structure.

[0019] In the present invention, it is preferable that the fuse is mounted on the first surface.

[0020] According to the present invention, a fuse is attached to the first surface portion of a substrate member, and an inverter circuit is attached to the second surface portion of the substrate member, so that the fuse and the inverter circuit are located on opposite sides of each other in the substrate member. As a result, the fuse is less likely to be affected by the heat of the inverter circuit, and the function of the fuse is less likely to be inhibited, so that the functionality of the inverter unit can be improved.

[0021] In the present invention, it is preferable that the plurality of inverter circuits supply power to each of the electric motors that drive different driven parts.

[0022] According to the present invention, in a plurality of electric motors that drive different driven parts, by setting each of the inverter circuits to a capacity corresponding to the capacity of the electric motor, an inverter unit capable of operating each of the plurality of electric motors independently without overloading can be obtained.

[0023] The work vehicle of the present invention is equipped with the inverter unit according to any one of claims 1 to 3.

[0024] According to the present invention, a work vehicle equipped with a compact inverter unit in which the arrangement of a plurality of inverter circuits is made space-saving can be obtained.

[0025] In the present invention, it is preferable that a right traveling device, a left traveling device, a work device, a first electric motor that drives the right traveling device, a second electric motor that drives the left traveling device, and a third electric motor that drives the work device are provided, and a first inverter circuit that supplies power to the first electric motor, a second inverter circuit that supplies power to the second electric motor, and a third inverter circuit that supplies power to the third electric motor are provided.

[0026] According to the present invention, when a first electric motor for driving the right travel device and a second electric motor for driving the left travel device are provided, the first inverter circuit and the second inverter circuit can operate the first electric motor and the second electric motor independently of each other, thereby driving the right travel device and the left travel device independently of each other.

[0027] This makes it possible to obtain various driving conditions such as forward and reverse movement with the right and left running gears driven at the same speed, right and left turns in forward (reverse) movement with one of the running gears driven at a lower speed than the other, right and left pivot turns with one of the running gears stopped and the other driven, and right super-pivot turns and left super-pivot turns with the right and left running gears driven in opposite directions, thus enabling the creation of a work vehicle with high driving performance.

[0028] According to the present invention, in addition to the first electric motor and the second transmission motor, a third electric motor and a third inverter circuit are provided to drive the work device. As a result, the third electric motor can be operated independently by the third inverter circuit, regardless of the driving state of the right and left travel devices by the first and second electric motors, and the work device can be operated appropriately according to the work state, thus enabling the creation of a work vehicle with high work performance.

[0029] In the present invention, it is preferable that the first inverter circuit, the second inverter circuit, and the third inverter circuit are mounted side by side on the substrate member such that the first inverter circuit is located to the right of the third inverter circuit and the second inverter circuit is located to the left of the third inverter circuit.

[0030] In work vehicles, the first electric motor that drives the right travel device is often located on the right side of the machine, the second electric motor that drives the left travel device is often located on the left side of the machine, and the third electric motor that drives the work device is often located in the center of the machine.

[0031] According to the present invention, the first inverter circuit for the right travel device and the first electric motor is located to the right of the third inverter circuit that supplies power to the third electric motor (working device). The second inverter circuit for the left travel device and the second electric motor is located to the left of the third inverter circuit that supplies power to the third electric motor (working device).

[0032] As a result, the first inverter circuit is positioned close to the first electric motor, and the second inverter circuit is positioned close to the second electric motor. This allows for shorter harnesses to be used between the first inverter circuit and the first electric motor, and between the second inverter circuit and the second electric motor, thereby simplifying the structure of the work vehicle. [Brief explanation of the drawing]

[0033] [Figure 1] This is a longitudinal cross-section of the inverter unit. [Figure 2] This is a schematic diagram showing the configuration of the circuit board components of the inverter unit. [Figure 3] This is a left side view of a ride-on lawnmower. [Figure 4] This is a plan view of a ride-on lawnmower. [Modes for carrying out the invention]

[0034] Inverter unit 1 is shown in Figures 1 and 2. An example of a work vehicle equipped with the inverter unit 1 shown in Figures 1 and 2, a riding-type lawnmower, is shown in Figures 3 and 4. In Figures 3 and 4, F indicates the forward direction, B indicates the backward direction, U indicates the upward direction, D indicates the downward direction, R indicates the right direction, and L indicates the left direction.

[0035] (Configuration of Inverter Unit 1) - 1 As shown in Figures 1 and 2, the inverter unit 1 includes a case 2, a circuit board 3, inverter circuits 11, 12, 13, a battery connector 4, output connectors 5, 6, 7, conductive wires 8, 15, 16, 17, multiple fuses 18, 19, a heat sink 21, and the like.

[0036] Case 2 has a main body 2a and a lid 2b. The main body 2a is rectangular in shape when viewed from above, with its top and bottom surfaces open. The lid 2b is flat and can be attached to and removed from the top surface of the main body 2a.

[0037] The circuit board component 3 is constructed in a flat plate shape using an insulator and is a power board to which conductive wires 8, 15, 16, and 17, which will be described later, are attached. The circuit board component 3 is attached to the main body 2a of the case 2 inside the case 2 and is supported by the case 2.

[0038] The battery connector 4 is attached to the main body 2a of the case 2 and connected to the circuit board 3. Three output connectors 5, 6, and 7 are attached to the main body 2a of the case 2 in a row and connected to the circuit board 3.

[0039] On the upper surface 3a and lower surface 3b of the substrate member 3, three inverter circuits 11, 12, and 13 are mounted on the lower surface 3b of the substrate member 3 so as to face the output connectors 5, 6, and 7, respectively. A DC-DC converter circuit 14 is mounted on the lower surface 3b of the substrate member 3.

[0040] The conductive wire 8 is connected across the inverter circuit 11 and the output connector 5, across the inverter circuit 12 and the output connector 6, and across the inverter circuit 13 and the output connector 7. The conductive wire 8 is attached to the upper surface 3a of the substrate member 3.

[0041] (Configuration of Inverter Unit 1) - 2 As shown in Figures 1 and 2, conductive wire 15 extends from the battery connector 4. Conductive wire 16 branches off from conductive wire 15 and is connected to inverter circuits 11, 12, and 13.

[0042] A fuse 18 is provided on each of the positive conductive wires 16, and also on the positive and negative conductive wires 15. The conductive wires 15, 16 and the fuse 18 are attached to the upper surface 3a of the substrate member 3. As a result, the fuse 18 is provided in the portions of the conductive wires 15, 16 corresponding to the multiple inverter circuits 11, 12, and 13.

[0043] Conductive wire 17 branches off from conductive wire 15 and is connected to the DC-DC converter circuit 14. A fuse 19 is provided on the positive conductive wire 17. Conductive wire 17 and fuse 19 are attached to the upper surface 3a of the substrate member 3.

[0044] (Configuration of Inverter Unit 1) - 3 As shown in Figures 1 and 2, the relay switch 9 is provided in the positive conductive wire 15, in the portion between the branching point to the conductive wire 16 and the fuse 18.

[0045] The main switch 10 is located on the positive conductive wire 17, between the branch portion from the conductive wire 15 and the fuse 19. The relay switch 9 and the main switch 10 are mounted on the upper surface 3a of the circuit board member 3.

[0046] When the main switch 10 is turned on, the relay switch 9 is also turned on in conjunction with it. When the main switch 10 is turned off, the relay switch 9 is also turned off in conjunction with it.

[0047] A heat-conducting insulator 20 is attached to the bottom of the inverter circuits 11, 12, and 13, and to the bottom of the DC-DC converter circuit 14. A single heatsink 21 is positioned on the underside of the main body 2a of the case 2, and the heatsink 21 is attached across the insulators 20 of the inverter circuits 11, 12, and 13, the insulator 20 of the DC-DC converter circuit 14, and the bottom of the main body 2a of the case 2.

[0048] As a result, the circuit board component 3, inverter circuits 11, 12, 13, DC-DC converter circuit 14, conductive wires 8, 15, 16, 17, fuses 18, 19, relay switch 9, and main switch 10 are housed in case 2. The open bottom surface of case 2 (main body 2a) is closed by the heat sink 21.

[0049] (Configuration of a ride-on lawnmower) Figures 3 and 4 show a ride-on lawnmower equipped with the inverter unit 1 shown in Figures 1 and 2. As shown in Figures 3 and 4, the ride-on lawnmower has right and left front wheels 30 supported at the front of the machine body 34, a right rear wheel 31 and a left rear wheel 32 supported at the rear of the machine body 34, a mower 33 attached to the lower part of the machine body 34 between the front wheels 30 and the right rear wheel 31 and left rear wheel 32, a driver's seat 35 and a lops frame 36 attached to the upper part of the machine body 34, etc.

[0050] The aircraft body 34 comprises right and left aircraft frames 37 running in the longitudinal direction, and a floor 38 connected across the right and left aircraft frames 37. A cockpit 35 is located at the rear of the floor 38, and the lower part of the lops frame 36 is connected to the aircraft frame 37. A battery 39 is mounted at the rear of the aircraft body 34.

[0051] (Configuration relating to the front wheel 30, the right rear wheel 31, and the left rear wheel 32) As shown in Figures 3 and 4, the right and left front wheels 30 are configured as caster wheels that can freely rotate around an axis along the vertical direction and are attached to the front of the machine frame 37.

[0052] The right reduction gear 40 is attached to the right aircraft frame 37. The right rear wheel 31 is attached to the right reduction gear 40, and the electric motor 41 is attached to the right reduction gear 40. Power from the electric motor 41 is transmitted to the right rear wheel 31 via the right reduction gear 40, thereby driving the right rear wheel 31.

[0053] The left reduction gear 40 is attached to the left aircraft frame 37. The left rear wheel 32 is attached to the left reduction gear 40, and the electric motor 42 is attached to the left reduction gear 40. Power from the electric motor 42 is transmitted to the left rear wheel 32 via the left reduction gear 40, driving the left rear wheel 32. As a result, the right rear wheel 31 and the left rear wheel 32 are driven independently by the electric motors 41 and 42.

[0054] (The composition of Mohr 33) As shown in Figures 3 and 4, the mower 33 has a mower deck 44 and a plurality of cutting blades 45 that are rotatably supported around a longitudinal axis inside the mower deck 44. An electric motor 43 is positioned between the right and left machine frame 37 and mounted in the left and right center of the rear of the mower deck 44, and the cutting blades 45 are driven by the electric motor 43.

[0055] (Placement status of inverter unit 1) As shown in Figures 3 and 4, the inverter unit 1 is located below the driver's seat 35. In this case, the inverter unit 1 is positioned such that inverter circuit 11 is located to the right of inverter circuit 13, inverter circuit 12 is located to the left of inverter circuit 13, and inverter circuits 11, 12, and 13 are aligned along the left-right direction.

[0056] As shown in Figure 2, the connector 39a of the battery 39 is connected to the battery connector 4 of the inverter unit 1. The connector 41a of the electric motor 41 is connected to the output connector 5 of the inverter unit 1. The connector 42a of the electric motor 42 is connected to the output connector 6 of the inverter unit 1. The connector 43a of the electric motor 43 is connected to the output connector 7 of the inverter unit 1.

[0057] As shown in Figures 3 and 4, when the driver's seat 35 is removed and the panel (not shown) below the driver's seat 35 is opened, the lid 2b of the case 2 (inverter unit 1) is exposed facing upward.

[0058] The worker can perform maintenance on the inverter unit 1 by removing the lid 2b of case 2. The worker can also remove the inverter unit 1 and perform maintenance on it.

[0059] (Operating status of inverter unit 1) - 1 As shown in Figures 1 and 2, power from the battery 39 is supplied to the inverter circuits 11, 12, and 13 via conductive wires 15 and 16 from the battery connector 4 of the inverter unit 1. Power from the battery 39 is supplied to the electric motors 41, 42, and 43 via output connectors 5, 6, and 7 from the inverter circuits 11, 12, and 13.

[0060] The power from the battery 39 is supplied from the battery connector 4 of the inverter unit 1 via the conductive wire 17 to the DC-DC converter circuit 14, where it is transformed into a low voltage and supplied to the control device (not shown) and electrical components (not shown) mounted on the riding lawnmower.

[0061] (Operating status of inverter unit 1) - 2 As shown in Figures 3 and 4, the right and left gear shift levers 46 are located on the right and left sides of the driver's seat 35. The gear shift levers 46 can be operated from the neutral position toward the forward and reverse directions, and the operating position of the gear shift levers 46 is input to a control device (not shown). The control device operates the inverter circuits 11 and 12 of the inverter unit 1 as described below.

[0062] When the right gear lever 46 is moved to the neutral position, the control device operates the inverter circuit 11, and the electric motor 41 stops. When the right gear lever 46 is moved to the forward position, the control device operates the inverter circuit 11, and the electric motor 41 operates in the forward direction. When the right gear lever 46 is moved to the reverse position, the control device operates the inverter circuit 11, and the electric motor 41 operates in the reverse direction.

[0063] When the left gear lever 46 is moved to the neutral position, the control device operates the inverter circuit 12, and the electric motor 42 stops. When the left gear lever 46 is moved to the forward position, the control device operates the inverter circuit 12, and the electric motor 42 operates in the forward direction. When the left gear lever 46 is moved to the reverse position, the control device operates the inverter circuit 12, and the electric motor 42 operates in the reverse direction.

[0064] As described above, by operating the right and left gear shift levers 46 independently of each other, the electric motors 41 and 42 operate independently of each other, and the right rear wheel 31 and the left rear wheel 32 are driven independently of each other.

[0065] The vehicle can perform forward and reverse movements with the right rear wheel 31 and the left rear wheel 32 driven at the same speed, as well as right and left turns in forward (reverse) movements with one of the right rear wheel 31 and the left rear wheel 32 driven at a lower speed than the other. It can also perform right and left pivot turns with one of the right rear wheel 31 and the left rear wheel 32 stopped and the other driven, as well as right super-pivot turns and left super-pivot turns with the right rear wheel 31 and the left rear wheel 32 driven in opposite directions.

[0066] (Operating status of inverter unit 1) - 3 As shown in Figures 1 to 4, in the mower 33, the control device operates the inverter circuit 13 so that the electric motor 43 operates at a constant speed in the forward direction, and the cutting blade 45 of the mower 33 is driven to rotate in the forward direction at a constant speed.

[0067] A cooling fan (not shown), which is driven by the power of an electric motor 43, is located below the inverter unit 1. Cooling air from the cooling fan is supplied to the electric motors 41, 42, and 43, and then supplied to the heat sink 21 of the inverter unit 1.

[0068] During movement or maintenance of the ride-on lawnmower, the control device and inverter circuit 13 can stop the electric motor 43. If a blockage occurs in the cutting blade 45 of the mower 33, the control device and inverter circuit 13 can reverse the operation of the electric motor 43 at a low speed.

[0069] (First alternative embodiment of the invention) In the inverter unit 1, two inverter circuits 11, 12, and 13 may be attached to the substrate member 3. Four, five, or six or more inverter circuits 11, 12, and 13 may be attached to the substrate member 3.

[0070] (Second alternative embodiment of the invention) In the inverter unit 1, the upper surface 3a of the substrate member 3 may become the second surface, and the lower surface 3b of the substrate member 3 may become the first surface. According to the above configuration, the inverter circuits 11, 12, 13, the DC-DC converter circuit 14, and the heat sink 21 are located on the upper surface of the substrate member 3. The conductive wires 8, 15, 16, 17 and the fuses 18, 19 are located on the lower surface of the substrate member 3.

[0071] (Third alternative form of the invention) The inverter unit 1 may be mounted on the work vehicle with the circuit board member 3 of the inverter unit 1 in an orientation aligned in the vertical direction. According to the above configuration, one left or right surface of the substrate member 3 becomes the first surface, and the other left or right surface of the substrate member 3 becomes the second surface. Alternatively, one front or rear surface of the substrate member 3 becomes the first surface, and the other front or rear surface of the substrate member 3 becomes the second surface.

[0072] (Fourth alternative embodiment of the invention) In the work vehicle, two electric motors 41, 42, and 43 may be provided, or four, five, or six or more electric motors 41, 42, and 43 may be provided.

[0073] (Fifth alternative embodiment of the invention) In the work vehicle, instead of the right rear wheel 31 and the left rear wheel 32, right and left crawler running devices (not shown) may be provided.

[0074] In the above configuration, the right and left front wheels 30 may be configured as wheels that are steered by a steering device (not shown) rather than caster wheels. The right and left front wheels 30 may be eliminated, and only the right and left crawler tracks (not shown) may be provided.

[0075] (Correspondence with claims) - 1 Inverter circuit 11 corresponds to the first inverter circuit 11. Inverter circuit 12 corresponds to the second inverter circuit 12. Inverter circuit 13 corresponds to the third inverter circuit 13. The upper surface 3a of the substrate member 3 corresponds to the first surface of the substrate member 3. The lower surface 3b of the substrate member 3 corresponds to the second surface of the substrate member 3. The conductive wires 15 and 16 correspond to the distribution circuit.

[0076] The right rear wheel 31 corresponds to the right running gear and is the driven part. The left rear wheel 32 corresponds to the left running gear and is the driven part. The mower 33 corresponds to the working device and is the driven part. Electric motor 41 corresponds to the first electric motor 41. Electric motor 42 corresponds to the second electric motor 42. Electric motor 43 corresponds to the third electric motor 43.

[0077] (Correspondence with claims) - 2 The inverter unit 1 is equipped with a battery connector 4 that can be connected to a battery 39, and multiple output connectors 5, 6, and 7 that can be connected to each of the multiple electric motors 41, 42, and 43.

[0078] The inverter unit 1 includes a plurality of inverter circuits 11, 12, and 13, each attached to a circuit board member 3 and connected to a plurality of output connectors 5, 6, and 7. A distribution circuit (conductive wires 15, 16) is also attached to the circuit board member 3 and supplies power supplied to the battery connector 4 to each of the plurality of inverter circuits 11, 12, and 13. A plurality of fuses 18 are also attached to the circuit board member 3 and are provided in the portions of the distribution circuit (conductive wires 15, 16) corresponding to the plurality of inverter circuits 11, 12, and 13.

[0079] (Correspondence with claims) - 3 The inverter unit 1 is equipped with a battery connector 4 and output connectors 5, 6, and 7, and a case 2 that houses a circuit board member 3, inverter circuits 11, 12, and 13, distribution circuits (conductive wires 15 and 16), and a fuse 18.

[0080] (Correspondence with claims) - 4 The inverter unit 1 is equipped with a heat sink 21 that is attached across multiple inverter circuits 11, 12, and 13.

[0081] (Correspondence with claims) - 5 In the inverter unit 1, the distribution circuit (conductive wires 15, 16) is attached to the first surface (upper surface 3a) on one side of the substrate member 3. The inverter circuits 11, 12, and 13 are attached to the second surface (lower surface 3b) of the substrate member 3, opposite to the first surface (upper surface 3a). The heat sink 21 is positioned on the side of the second surface (lower surface 3b) and is attached across the multiple inverter circuits 11, 12, and 13.

[0082] (Correspondence with claims) - 6 In the inverter unit 1, the fuse 18 is mounted on the first surface (top surface 3a). Multiple inverter circuits 11, 12, and 13 supply power to electric motors 41, 42, and 43 that drive different driven parts (right rear wheel 31, left rear wheel 32, and moor 33).

[0083] (Correspondence with claims) - 7 The work vehicle is equipped with an inverter unit 1 as described in any one of claims 1 to 6.

[0084] (Correspondence with claims) - 8 The work vehicle is equipped with a right-side running gear (right rear wheel 31), a left-side running gear (left rear wheel 32), and a work device (mower 33). The vehicle is equipped with a first electric motor 41 that drives the right travel device (right rear wheel 31), a second electric motor 42 that drives the left travel device (left rear wheel 32), and a third electric motor 43 that drives the work device (mower 33).

[0085] The inverter unit 1 includes a first inverter circuit 11 that supplies power to a first electric motor 41, a second inverter circuit 12 that supplies power to a second electric motor 42, and a third inverter circuit 13 that supplies power to a third electric motor 43.

[0086] The first inverter circuit 11, the second inverter circuit 12, and the third inverter circuit 13 are mounted side-by-side on the substrate member 3 such that the first inverter circuit 11 is located to the right of the third inverter circuit 13, and the second inverter circuit 12 is located to the left of the third inverter circuit 13. [Industrial applicability]

[0087] The present invention can be applied not only to inverter units 1 mounted on work vehicles, but also to inverter units 1 that supply power to electric motors that drive stationary generators, pumps, etc. This invention can be applied not only to ride-on lawnmowers, but also to agricultural work vehicles such as tractors and combine harvesters, as well as construction work vehicles such as backhoes and wheel loaders. [Explanation of symbols]

[0088] 1 Inverter Unit 2 cases 3. Substrate components 3a First side 3b Second side part 4. Battery connector 5 Output Connectors 6 output connectors 7 Output connector 11. Inverter Circuit (First Inverter Circuit) 12. Inverter Circuit (Second Inverter Circuit) 13. Inverter Circuit (Third Inverter Circuit) 15 Conductive wire (distribution circuit) 16 Conductive wires (distribution circuits) 18 fuses 21 Heatsink 31 Right rear wheel (right running gear) (driven part) 32. Left rear wheel (left running gear) (driven part) 33. Mower (working device) (driven part) 39 batteries 41 Electric motor (first electric motor) 42. Electric motor (second electric motor) 43. Electric motor (third electric motor)

Claims

1. A battery connector that can be connected to the battery, Multiple output connectors that can be connected to each of the multiple electric motors, Substrate material and Multiple inverter circuits are attached to the substrate member and connected to each of the multiple output connectors, A distribution circuit attached to the substrate member, which supplies power supplied to the battery connector to each of the plurality of inverter circuits, An inverter unit comprising: a plurality of fuses attached to the substrate member and provided in the portion of the distribution circuit corresponding to the plurality of inverter circuits;

2. The inverter unit according to claim 1, wherein the battery connector and the output connector are attached, and a case is provided for housing the circuit board member, the inverter circuit, the distribution circuit, and the fuse.

3. The inverter unit according to claim 1, further comprising a heat sink attached across multiple inverter circuits.

4. The distribution circuit is attached to one of the first surfaces of the substrate member. The inverter circuit is mounted on the second surface of the substrate member opposite to the first surface. The inverter unit according to claim 3, wherein the heat sink is positioned on the side of the second surface and is mounted across a plurality of inverter circuits.

5. The inverter unit according to claim 4, wherein the fuse is mounted on the first surface.

6. The inverter unit according to claim 1, wherein the plurality of inverter circuits supply power to each of the electric motors that drive different driven parts.

7. A work vehicle equipped with an inverter unit according to any one of claims 1 to 6.

8. Right-hand travel device, left-hand travel device, and work device, The system is equipped with a first electric motor for driving the right travel device, a second electric motor for driving the left travel device, and a third electric motor for driving the work device. The work vehicle according to claim 7, further comprising: a first inverter circuit for supplying power to the first electric motor; a second inverter circuit for supplying power to the second electric motor; and a third inverter circuit for supplying power to the third electric motor.

9. The work vehicle according to claim 8, wherein the first inverter circuit, the second inverter circuit, and the third inverter circuit are mounted side by side on the substrate member such that the first inverter circuit is located to the right of the third inverter circuit and the second inverter circuit is located to the left of the third inverter circuit.

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