JP6979317B2 - Transport vehicle - Google Patents

Description

The present invention relates to a transport vehicle used to transport heavy objects in a factory.

Patent Document 1 describes a transport vehicle including a vehicle body including a loading platform on which a heavy object is mounted, two engines, and an elevating device for raising and lowering the loading platform. This transport vehicle has a first hydraulic circuit in which a first tank and a plurality of elevating devices on the front side are connected, and a second hydraulic circuit in which a second tank and a plurality of elevating devices on the rear side are connected. The first pump arranged in the first hydraulic circuit and the second pump arranged in the second hydraulic circuit are driven by different engines. In this carrier, it is described that one engine is stopped and the loading platform is raised and lowered by driving the other engine.

JP-A-2017-7370

In this transport vehicle, the first hydraulic circuit and the second hydraulic circuit are connected when one engine is stopped and the vehicle travels by driving the other engine. Therefore, oil is sent from the hydraulic circuit of the drive side engine to the hydraulic circuit of the stop side engine, but when the oil is returned to the tank from the plurality of elevating devices after the elevating operation is completed, the amount of oil in the first tank And the amount of oil in the second tank become unbalanced, and there is a danger that oil will leak from the tank or air will be mixed.

Therefore, an object of the present invention is to provide a transport vehicle capable of eliminating an imbalance between the amount of oil in the first tank and the amount of oil in the second tank.

The transport vehicle according to the first invention includes a vehicle body including a loading platform and a plurality of traveling devices, a first hydraulic circuit in which a first tank and a first hydraulic device are connected, and a second tank and a second hydraulic device. The connected second hydraulic circuit, the first engine for driving the first pump arranged in the first hydraulic circuit, the second engine for driving the second pump arranged in the second hydraulic circuit, and the above. The first detecting means for detecting the amount of oil in the first tank, the second detecting means for detecting the amount of oil in the second tank, and the amount of oil in the first tank detected by the first detecting means. And, based on the amount of oil in the second tank detected by the second detection means, the oil is sent from one tank of the first tank and the second tank to the other tank. It is provided with a first hydraulic circuit, the second hydraulic circuit, the first engine, and a control unit for controlling the second engine.

In this transport vehicle, when only one of the first engine and the second engine is driven, the state is switched so that the first hydraulic circuit and the second hydraulic circuit communicate with each other, and only the oil in the tank on the driven engine side is used. Is sent to the first hydraulic device and the second hydraulic device, so that the amount of oil in the first tank and the amount of oil in the second tank become unbalanced. At this time, the oil is sent from the tank having the larger amount of oil in the first tank and the second tank to the tank having the smaller amount of oil, so that the amount of oil in the first tank and the amount of oil in the second tank are unbalanced. It can be resolved.

In the first invention, the transport vehicle according to the second invention has a communication state in which the portion downstream of the first pump of the first hydraulic circuit and the portion downstream of the second pump of the second hydraulic circuit are communicated with each other. The first switching means for switching to one of the non-communication states that do not communicate with each other, the upstream portion of the first hydraulic circuit from the first pump, and the upstream portion of the second hydraulic circuit from the second pump communicate with each other. It is provided with a second switching means for switching between a communication state in which communication is performed and a non-communication state in which communication is not performed.

In this transport vehicle, when only one of the first engine and the second engine is driven, oil can be sent from the drive side tank to the stop side tank by setting the first switching means in a communicating state. By setting the second switching means to the communication state, oil can be sent from the stop side tank to the drive side tank.

In the first or second invention, the transport vehicle according to the third invention includes a plurality of cylinders for raising and lowering the loading platform, and the first hydraulic device is a first cylinder included in the plurality of cylinders. The second hydraulic device is a second cylinder included in the plurality of cylinders.

In this carrier, the loading platform can be raised and lowered when only one of the first engine and the second engine is driven.

In any one of the first to third inventions, the transport vehicle according to the fourth invention has the control unit, the oil amount in the first tank detected by the first detection means, and the second. When any of the oil amounts in the second tank detected by the detection means exceeds the upper limit amount, the oil is sent from the tank having the upper limit amount or more to the other tank. It controls the circuit, the second hydraulic circuit, the first engine and the second engine.

In this transport vehicle, when either the amount of oil in the first tank or the amount of oil in the second tank exceeds the upper limit amount, oil is sent from the tank having the upper limit amount or more to the other tank. Therefore, when the amount of oil in the tank exceeds the upper limit, it is possible to prevent the oil from overflowing.

In the fourth aspect of the invention, the transport vehicle according to the fifth invention has the control unit detected by the oil amount in the first tank detected by the first detection means and by the second detection means. When any of the amount of oil in the second tank exceeds the predetermined range set between the upper limit amount and the lower limit amount, oil is sent from the tank exceeding the predetermined range to the other tank. Moreover, either the amount of oil in the first tank detected by the first detection means or the amount of oil in the second tank detected by the second detection means is less than the predetermined range. The first hydraulic circuit, the second hydraulic circuit, the first engine, and the second engine are controlled so that oil is sent from the other tank to the tank that has fallen below the predetermined range.

In this transport vehicle, when either the amount of oil in the first tank or the amount of oil in the second tank exceeds the predetermined range set between the upper limit amount and the lower limit amount, the tank that exceeds the predetermined range is used. When oil is sent to the other tank and either the amount of oil in the first tank or the amount of oil in the second tank falls below the predetermined range, the other tank goes to the tank that falls below the predetermined range. Oil is sent from. Therefore, the imbalance can be eliminated by the time the amount of oil in the first tank and the amount of oil in the second tank increase to the upper limit.

In the fifth invention, the carrier vehicle according to the sixth invention has a first engine drive state in which the first engine is driven and the second engine is not driven, and the first engine is driven and the first engine is driven. It is possible to take a second engine drive state in which the engine is not driven and a third engine drive state in which the first engine is driven and the second engine is driven, and the first engine drive state is the first. The oil amount in the predetermined range for the tank and the oil amount in the predetermined range for the second tank in the second engine driven state are the oil amounts in the first tank and the second tank in the third engine driven state. The amount of oil is less than the above-mentioned predetermined range.

In this carrier, the amount of oil in a predetermined range when only one of the first engine and the second engine is driven is less than the amount of oil in the predetermined range when the first engine and the second engine are driven. Therefore, if the amount of oil in each predetermined range is the same, when only one of the first engine and the second engine is driven to raise the loading platform and then lower it, the oil is the engine on the driving side. However, when the amount of oil in the tank reaches the upper limit, it is necessary to interrupt the lowering of the loading platform and eliminate the imbalance in the amount of oil in the tank, which reduces the operating rate of lowering the loading platform. Can be suppressed.

In any one of the first to sixth inventions, the transport vehicle according to the seventh invention has the control unit, the oil amount in the first tank detected by the first detection means, and the second. When any of the oil amounts in the second tank detected by the detection means is equal to or less than the lower limit amount, the oil is sent from the other tank to the tank having the lower limit amount or less. It controls the circuit, the second hydraulic circuit, the first engine and the second engine.

In this transport vehicle, when either the amount of oil in the first tank or the amount of oil in the second tank becomes equal to or less than the lower limit, oil is sent from the other tank to the tank having the lower limit or less. Therefore, the imbalance between the amount of oil in the first tank and the amount of oil in the second tank can be eliminated.

In the seventh invention, the carrier vehicle according to the eighth invention has a first engine drive state in which the first engine is driven and the second engine is not driven, and the first engine in which the second engine is driven and the first engine is driven. It is possible to take a second engine drive state in which the engine is not driven and a third engine drive state in which the first engine is driven and the second engine is driven, and the first engine drive state is the first. The lower limit amount for the tank and the lower limit amount for the second tank in the second engine drive state are smaller than the lower limit amount for the first tank and the second tank in the third engine drive state. ..

In this transport vehicle, the lower limit amount when only one of the first engine and the second engine is driven is smaller than the lower limit amount when the first engine and the second engine are driven. Therefore, if the lower limit of each is the same, when only one of the first engine and the second engine is driven to raise the loading platform and then lower the loading platform, oil is applied to the tank of the engine on the driving side. However, when the amount of oil in the tank reaches the upper limit, it is necessary to interrupt the lowering of the loading platform and eliminate the imbalance in the amount of oil in the tank, which suppresses the decrease in the operating rate of lowering the loading platform. can.

As described above, according to the present invention, the following effects can be obtained.
In the first invention, when only one of the first engine and the second engine is driven, the oil in the tank on the engine side is switched to a state in which the first hydraulic circuit and the second hydraulic circuit communicate with each other. Since only the oil is sent to the first hydraulic device and the second hydraulic device, the amount of oil in the first tank and the amount of oil in the second tank become unbalanced. At this time, the oil is sent from the tank having the larger amount of oil in the first tank and the second tank to the tank having the smaller amount of oil, so that the amount of oil in the first tank and the amount of oil in the second tank are unbalanced. It can be resolved.
In the second invention, when only one of the first engine and the second engine is driven, oil can be sent from the drive side tank to the stop side tank by setting the first switching means in the communication state. By setting the second switching means to the communication state, oil can be sent from the stop side tank to the drive side tank.
In the third invention, the loading platform can be raised and lowered when only one of the first engine and the second engine is driven.

In the fourth invention, when either the amount of oil in the first tank or the amount of oil in the second tank exceeds the upper limit, oil is sent from the tank having the upper limit or more to the other tank. .. Therefore, when the amount of oil in the tank exceeds the upper limit, it is possible to prevent the oil from overflowing.
In the fifth invention, when either the amount of oil in the first tank or the amount of oil in the second tank exceeds a predetermined range set between the upper limit amount and the lower limit amount, the tank exceeds the predetermined range. When oil is sent from the tank to the other tank and either the amount of oil in the first tank or the amount of oil in the second tank falls below the predetermined range, the other tank falls below the predetermined range. Oil is sent from the tank. Therefore, the imbalance can be eliminated by the time the amount of oil in the first tank and the amount of oil in the second tank increase to the upper limit.
In the sixth invention, the amount of oil in a predetermined range when only one of the first engine and the second engine is driven is smaller than the amount of oil in the predetermined range when the first engine and the second engine are driven. Therefore, if the amount of oil in each predetermined range is the same, when only one of the first engine and the second engine is driven to raise the loading platform and then lower it, the oil is the engine on the driving side. However, when the amount of oil in the tank reaches the upper limit, it is necessary to interrupt the lowering of the loading platform and eliminate the imbalance in the amount of oil in the tank, which reduces the operating rate of lowering the loading platform. Can be suppressed.

In the seventh invention, when either the amount of oil in the first tank or the amount of oil in the second tank becomes equal to or less than the lower limit, oil is sent from the other tank to the tank having the lower limit or less. .. Therefore, the imbalance between the amount of oil in the first tank and the amount of oil in the second tank can be eliminated.
In the eighth invention, the lower limit amount when only one of the first engine and the second engine is driven is smaller than the lower limit amount when the first engine and the second engine are driven. Therefore, if the lower limit of each is the same, when only one of the first engine and the second engine is driven to raise the loading platform and then lower the loading platform, oil is applied to the tank of the engine on the driving side. However, when the amount of oil in the tank reaches the upper limit, it is necessary to interrupt the lowering of the loading platform and eliminate the imbalance in the amount of oil in the tank, which suppresses the decrease in the operating rate of lowering the loading platform. can.

It is a top view of the transport vehicle which concerns on embodiment of this invention. It is a right side view of the transport vehicle of FIG. It is a figure which shows the hydraulic circuit of the transport vehicle of FIG. It is a figure which shows the normal mode and the energy saving mode of the transport vehicle of FIG. It is a figure which shows the operation of the 1st energy saving mode. It is a figure which shows the operation of the 2nd energy saving mode. It is a figure which shows the operation of the 3rd energy saving mode. It is a figure which shows the upper limit value, the predetermined range, and the lower limit value set in the 1st tank and the 2nd tank.

Hereinafter, the transport vehicle according to the embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the transport vehicle 1 is used for transporting heavy objects in a factory, and has a substantially rectangular parallelepiped shape that is long in the front-rear direction as a whole. The transport vehicle 1 includes a vehicle body 3 including a loading platform 2 and a plurality of traveling devices A1-A12. The vehicle body 3 has a rectangular shape in a plan view, and its upper surface is a loading platform 2.

The transport vehicle 1 has a first cab 10a at one end in the front-rear direction of the vehicle body 3 and a second cab 10b at the other end in order to change the traveling direction back and forth. Therefore, in order to change the traveling direction of the transport vehicle 1 traveling forward with the first cab 10a as the front side in the opposite direction, the driver switches from the first cab 10a to the second cab 10b and operates. In the following, the side of the transport vehicle 1 provided with the first cab 10a is defined as the front side of the transport vehicle 1.

The transport vehicle 1 includes a first engine 4a for driving the first traveling device A1-A6 included in the plurality of traveling devices A1-A12, and a second traveling device A7 included in the plurality of traveling devices A1-A12. -Has a second engine 4b for driving the A12. The first engine 4a is arranged on the left side behind the first cab 10a, and the second engine 4b is arranged on the right side in front of the first cab 10a.

As shown in FIGS. 1 and 2, the transport vehicle 1 has a total of 12 traveling devices A1-A12, which are 6 rows in the front-rear direction and 2 in the left-right direction of the vehicle body 3. The traveling devices A1-A4 and A9-A12 each include an axle, four wheels fixed to the axle, and a swing arm to rotatably support the axle. Each of the traveling devices A5-A8 includes an axle, two wheels fixed to the axle, and a swing arm for rotatably supporting the axle.

The first transmission 6a is arranged inside the traveling devices A1-A4, and the second transmission 6b is arranged inside the traveling devices A9-A12. The first transmission 6a is connected to the first engine 4a by the first shaft 7a, and the second transmission 6b is connected to the second engine 4b by the second shaft 7a. The traveling device A1-A6 is connected to the first transmission 6a by the first propeller shaft 8a, and the traveling device A7-A12 is connected to the second transmission 6b by the second propeller shaft 8b.

Therefore, the power of the first engine 4a is transmitted to the first transmission 6a via the first shaft 7a and to the first traveling device A1-A6 via the first propeller shaft 8a. The power of the second engine 4b is transmitted to the second transmission 6b via the second shaft 7a, and is transmitted to the second traveling device A7-A12 via the second propeller shaft 8b. The first transmission 6a is configured to be able to switch between a state in which the power of the first engine 4a can be transmitted to the first traveling devices A1-A6 and a state in which the power cannot be transmitted to the first traveling devices A1-A6. The second transmission 6b is configured to be able to switch between a state in which the power of the second engine 4b can be transmitted to the second traveling device A7-A12 and a state in which the power cannot be transmitted to the second traveling device A7-A12.

In the present embodiment, the first shaft 7a, the first transmission 6a, and the first propeller shaft 8a are first power transmission devices that transmit the power of the first engine 4a to the first traveling devices A1-A6, and are the second. The shaft 7a, the second transmission 6b, and the second propeller shaft 8b are second power transmission devices that transmit the power of the second engine 4b to the second traveling device A7-A12.

In the first engine drive state in which the first engine 4a is driven and the second engine 4b is not driven, the first transmission 6a (first power transmission device) can transmit power, and the second transmission 6b (second power). The transmission device) is controlled so as not to transmit power.

In the second engine drive state in which the second engine 4b is driven and the first engine 4a is not driven, the second transmission 6b (second power transmission device) can transmit power, and the first transmission 6a (first power transmission) can be transmitted. The transmission device) is controlled so as not to transmit power.

The transport vehicle 1 further includes cylinders a1-a12 for raising and lowering the loading platform 2. The cylinders a1-a12 are arranged so as to correspond to each of the traveling devices A1-A12. The cylinders a1-a12 move the loading platform 2 up and down by expanding and contracting the rod. Therefore, for example, the loading platform 2 can be raised by extending the rods of the cylinders provided in all the traveling devices A1-A12 by the same length. By contracting the rods of all the cylinders from the ascending position, the loading platform 2 can be lowered.

The transport vehicle 1 has a first tank 5a and a second tank 5b, and as shown in FIG. 3, a first hydraulic circuit 11a to which the first tank 5a and the first cylinder a1-a6 are connected and a second hydraulic circuit 11a. It has a second hydraulic circuit 11b to which the tank 5b and the second cylinder a7-a12 are connected. The first tank 5a is arranged on the right side behind the first cab 10a, and the second tank 5b is arranged on the left side in front of the first cab 10a.

The first hydraulic circuit 11a connects the first tank 5a and the first cylinders a1-a6, and the first pump 12a is arranged. The first pump 12a is driven by the first engine 4a. In the first hydraulic circuit 11a, the switching valve C1a is arranged between the first tank 5a and the first pump 12a. The first hydraulic circuit 11a is composed of a hydraulic circuit 11aa that branches on the downstream side of the first pump 12a and is connected to the first cylinders a1-a3 and a hydraulic circuit 11ab connected to the first cylinders a4-a6. Cylinder. A switching valve C2a is arranged in the hydraulic circuit 11aa, and a switching valve C3 is arranged in the hydraulic circuit 11ab.

The second hydraulic circuit 11b connects the second tank 5b and the second cylinder a7-a12, and the second pump is arranged. The second pump is driven by the second engine 4b. In the second hydraulic circuit 11b, the switching valve C1b is arranged between the second tank 5b and the second pump 12b. The second hydraulic circuit 11b is composed of a hydraulic circuit 11ba that branches on the downstream side of the second pump 12b and is connected to the second cylinder a7-a9 and a hydraulic circuit 11bb connected to the second cylinder a10-a12. Cylinder. A switching valve C2b is arranged in the hydraulic circuit 11ba, and a switching valve C3b is arranged in the hydraulic circuit 11bb.

Switching valves C4a and C4b, which are switching means, are arranged in the hydraulic circuit of the transport vehicle 1, and the first hydraulic circuit 11a and the second hydraulic circuit 11b are in a state of communicating with each other by the switching valves C4a and C4b and in a state of not communicating with each other. It is configured to be switchable to either. The switching valve C2a, the switching valve C3a, the switching valve C2b, and the switching valve C3b are connected by a hydraulic circuit 11ca, and the portion between the first pump 12a, the switching valve C2a, and the switching valve C3a is switched with the second pump 12b. The portion between the valve C2b and the switching valve C3b is connected by the hydraulic circuit 11cc.

A switching valve C4a is arranged in the hydraulic circuit 11ca, and by switching the switching valve C4a, it is possible to switch between a state in which the first hydraulic circuit 11a and the second hydraulic circuit 11b communicate with each other and a state in which the second hydraulic circuit 11b does not communicate with each other. A switching valve C4b is arranged in the hydraulic circuit 11cb, and by switching the switching valve C4b, it is possible to switch between a state in which the first hydraulic circuit 11a and the second hydraulic circuit 11b communicate with each other and a state in which the second hydraulic circuit 11b does not communicate with each other. In the present embodiment, the switching valve C4b has a portion downstream of the first pump 12a of the first hydraulic circuit 11a (the discharge side from the pump) and a portion downstream of the second pump 12b of the second hydraulic circuit 11b (from the pump). This is the first switching means for switching between a communication state in which communication with the discharge side) and a non-communication state in which communication is not performed.

In the hydraulic circuit 11ca, the portion between the switching valve C2a and the switching valve C3a is connected to the first tank 5a via the switching valve C5a, and the portion between the switching valve C2b and the switching valve C3b is the switching valve C5b. It is connected to the second tank 5b via.

The portion between the first tank 5a and the first pump 12a in the first hydraulic circuit 11a and the portion between the first tank 5a and the first pump 12a in the second hydraulic circuit 11b are connected by the hydraulic circuit 11cc. Will be done. A switching valve C4c, which is a switching means, is arranged in the hydraulic circuit 11cc. In the present embodiment, the switching valve C4c is a portion upstream of the first pump 12a of the first hydraulic circuit 11a (supply side to the pump) and a portion upstream of the second pump 12b of the second hydraulic circuit 11b (to the pump). This is a second switching means for switching between a communication state in which communication with the supply side) and a non-communication state in which communication is not performed.

Therefore, when the first engine 4a and the second engine 4b are driven by switching the switching valves C4a-C4c and the loading platform 2 is raised and lowered, the first hydraulic circuit 11a and the second hydraulic circuit 11b communicate with each other. In this state, the first pump 12a sends oil to the first cylinders a1-a6, and the second pump 12b sends oil to the second cylinders a7-a12. When only the first engine 4a is driven and the loading platform 2 is raised and lowered, the first cylinder a1-a6 and the first cylinder a1-a6 and the first hydraulic circuit 12a are in a state where the first hydraulic circuit 11a and the second hydraulic circuit 11b are in communication with each other. Oil is sent to the second cylinders a7-a12. When only the second engine 4b is driven and the loading platform 2 is raised and lowered, the first cylinder a1-a6 and the first cylinder a1-a6 and the second hydraulic circuit 12b are used in a state where the first hydraulic circuit 11a and the second hydraulic circuit 11b are in communication with each other. Oil is sent to the second cylinders a7-a12.

A first detection sensor T1 for detecting the amount of oil is arranged in the first tank 5a, and a second detection sensor T2 for detecting the amount of oil is arranged in the second tank 5b.

In the carrier 1 of the present embodiment, the first engine 4a, the second engine 4b, the first transmission 6a, the second transmission 6b, the switching valves C1a, C2a, C1b, C2b, C3b, C4a, C4b, C5a, C5b are Connected to the control unit. Therefore, the control unit controls the first engine 4a and the second engine 4b, and also controls the first transmission 6a and the second transmission 6b based on the driving states of the first engine 4a and the second engine 4b. The control unit controls the first pump 12a and the second pump 12b by controlling the first engine 4a and the second engine 4b, and also controls the switching valves C1a, C2a, C1b, C2b, C3b, C4a, C4b, C5a. , C5b controls the hydraulic circuit of the transport vehicle 1.

In the transport vehicle 1 of the present embodiment, the first engine drive state in which the first engine 4a is driven and the second engine 4b is not driven, and the second engine drive state in which the second engine 4b is driven and the first engine 4a is not driven. And a third engine drive state in which the first engine 4a is driven and the second engine 4b is driven. Therefore, in the transport vehicle 1, the first engine 4a and the first engine 4a are based on the height of the loading platform 2 (whether it is the lower limit height or the traveling height) and the load (whether there is a heavy object on the loading platform 2). The second engine 4b is controlled.

In the transport vehicle 1 of the present embodiment, as shown in FIG. 4, either a normal mode or an energy saving mode can be selected. The energy saving mode includes a first energy saving mode, a second energy saving mode, and a third energy saving mode.

The states of the transport vehicle 1 include a lower limit height state in which the loading platform 2 is the lower limit height, a vertical raising / lowering state in which the loading platform 2 moves up and down, and a loading platform 2 having a traveling height and a heavy object on the loading platform 2. There is a light load state where there is no load, and a heavy load state where the loading platform 2 is at the traveling height and there is a heavy object on the loading platform 2. In the transport vehicle 1, the loading platform 2 may have an upper limit height higher than the traveling height so that the loading platform 2 does not come into contact with the traveling path when the unevenness of the traveling path is large. It is one of a height state, a vertical lift state, a light load state, and a heavy load state. In the transport vehicle 1, pressure sensors are arranged in the first cylinders a1-a6 and the second cylinders a7-a12, respectively. Therefore, based on the pressure detected by the pressure sensors of the first cylinder a1-a6 and the second cylinder a7-a12, the weight of the heavy object on the loading platform 2 (the weight of the loading platform 2 and the weight of the heavy object on the loading platform 2). And total) is detected. In the present embodiment, when the weight of the heavy object on the loading platform 2 based on the pressure detected by the pressure sensors of the first cylinder a1-a6 and the second cylinder a7-a12 is the same as the weight of the loading platform 2, the loading platform 2 is used. 2 It is considered that there is no heavy object on the top.

The normal mode is a state in which the first engine 4a is driven and the second engine 4b is driven (third engine driving state) in any of the lower limit height state, the up / down elevating state, the light load state, and the heavy load state. It is a mode.

In the first energy saving mode, the first engine 4a is driven and the second engine 4b is driven (third engine drive state) in the up / down elevation state and the heavy load state, and the lower limit height state and the light load state are set. In the state, in the mode of the first engine drive state in which the first engine 4a is driven and the second engine 4b is not driven, or the second engine drive state in which the second engine 4b is driven and the first engine 4a is not driven. be.

In the second energy saving mode, in the heavy load state, the first engine 4a is driven and the second engine 4b is driven (third engine drive state), and the lower limit height state, the vertical lift state, and the light load state are set. In the state, in the mode of the first engine drive state in which the first engine 4a is driven and the second engine 4b is not driven, or the second engine drive state in which the second engine 4b is driven and the first engine 4a is not driven. be.

In the third energy saving mode, the first engine 4a is driven and the second engine 4b is driven (third engine drive state) in the lower limit height state, the up / down elevation state, and the heavy load state, and the light load is applied. In the state, in the mode of the first engine drive state in which the first engine 4a is driven and the second engine 4b is not driven, or the second engine drive state in which the second engine 4b is driven and the first engine 4a is not driven. be.

The operation of the first energy saving mode will be described with reference to FIG.

When the power of the transport vehicle 1 is turned on in S1, it is determined in S2 whether the first energy saving mode is selected. In S2, when the energy saving mode is not selected, the operation is also performed in the normal mode. When it is determined in S2 that the first energy saving mode is selected, the driver's cab is selected in S3. Hereinafter, the operation when the first cab 10a is selected will be described. In S3, the operation when the second cab 10b is selected is the same as the operation when the first cab 10a is selected, so the description thereof will be omitted.

When the first cab 10a is selected in S3, it is determined in S4 whether the first engine 4a is being driven. When the first engine 4a is being driven, it is determined in S5 whether the second engine 4b is being driven. When the second engine 4b is not driven in S5, it is determined in S6 whether the running height is reached. When it is determined in S6 that the running height is not reached, and then in S7, when an instruction for ascending / descending operation is given, it is determined in S8 whether the second engine 4b is being driven, and when the second engine 4b is being driven. Is confirmed in S9 that the first engine 4a and the second engine 4b are being driven, and in S10, the ascending / descending operation is started.

When the first engine 4a is not driven in S4, it is determined in S11 whether the second engine 4b is driven. In S11, when the second engine 4b is not driven, in S12, the first engine 4a is manually driven and then shifts to S5. When the second engine 4b is driven in S11, the first engine 4a is automatically driven in S13. In S14, it is determined whether the running height is reached, and if it is not the running height, the second engine 4b is automatically stopped in S15 and shifts to S7. When it is determined in S14 that the running height is high, it is determined in S16 whether the load is heavy, and when the load is not heavy, the second engine 4b is automatically stopped in S15 and shifts to S7. When it is determined in S16 that the load is heavy, the process shifts to S7.

In S6, when it is determined that the running height is high, it is determined in S17 whether the load is heavy, and when it is not heavy load, the process proceeds to S7. When it is determined in S17 that the load is heavy, the second engine 4b is automatically driven in S18 and then shifts to S7. When the second engine 4b is not driven in S8, the second engine 4b is automatically driven in S19 and then shifts to S7.

After the ascending / descending operation is started in S10, it is determined in S20 whether the driver's cab has been changed, and if the driver's cab is not changed, the ascending / descending operation is stopped in S21. After that, in S22, it is determined whether the running height is reached, and if it is not the running height, the second engine 4b is automatically stopped in S23, and then the engine shifts to S3.

When it is determined in S22 that the running height is high, it is determined in S24 whether the load is heavy, and when it is not heavy load, the process proceeds to S23. When it is determined in S24 that the load is heavy, the process shifts to S3. When the driver's cab is changed in S20, the process shifts to S3.

The operation of the second energy saving mode will be described with reference to FIG.

When the power of the transport vehicle 1 is turned on in S101, it is determined in S102 whether the second energy saving mode is selected. In S102, when the energy saving mode is not selected, the operation of the normal mode is performed. When it is determined in S102 that the second energy saving mode is selected, the driver's cab is selected in S103. Hereinafter, the operation when the first cab 10a is selected will be described. In S103, the operation when the second cab 10b is selected is the same as the operation when the first cab 10a is selected, so the description thereof will be omitted.

When the first cab 10a is selected in S103, it is determined in S104 whether the first engine 4a is being driven. When the first engine 4a is being driven, it is determined in S105 whether the second engine 4b is being driven. When the second engine 4b is not driven in S105, it is determined in S106 whether the running height is reached. If there is an instruction for the ascending / descending operation after it is determined in S106 that the height is not the traveling height, it is determined in S107 whether the instruction is for the descending operation. When the lowering operation is instructed, it is determined in S108 whether the second engine 4b is driven, and when the second engine 4b is not driven, in S109, the first engine 4a is driven during the ascent. It is judged whether there is.

When it is determined in S108 that the second engine 4b is being driven, in S110, the second engine 4b is automatically stopped and then the process proceeds to S109. When it is determined in S109 that the oil is being climbed by driving the first engine 4a, the oil is returned to the first tank 5a in S111, and then the descending operation is started in S112.

When the first engine 4a is not driven in S104, it is determined in S113 whether the second engine 4b is driven. When the second engine 4b is not driven in S113, the first engine 4a is manually driven in S114 and then the process proceeds to S105. When the second engine 4b is driven in S113, the first engine 4a is automatically driven in S115. In S116, it is determined whether it is the running height, and if it is not the behavioral height, it returns to S116.

When it is determined in S116 that the running height is high, it is determined in S117 whether the load is heavy, and when the load is not heavy, the second engine 4b is automatically stopped in S118 to shift to S107. When it is determined in S117 that the load is heavy, the process shifts to S107.

In S106, when it is determined that the running height is high, it is determined in S119 whether the load is heavy, and when it is not heavy load, the process proceeds to S107. When it is determined in S119 that the load is heavy, the second engine 4b is automatically driven in S120 to shift to S107.

In S107, when it is determined that the instruction is not a descending operation (when the instruction is ascending), it is determined in S121 whether the second engine 4b is being driven, and when the second engine is not driven, S122 is determined. In, it is determined whether it is the lower limit height. When it is determined in S121 that the second engine 4b is being driven, in S123, after the second engine 4b is automatically stopped, the process proceeds to S122. When it is determined in S122 that the height is not the lower limit, it is determined in S124 whether the vehicle is in the process of climbing by driving the first engine 4a. When it is determined in S124 that the climbing is not in progress due to the drive of the first engine 4a, the climbing operation is terminated in S125. When it is determined in S122 that the height is the lower limit, the ascending operation is started by driving the first engine 4a in S126.

When it is determined in S109 that the engine is not in the process of climbing due to the drive of the first engine 4a, the oil is returned to the second tank in S127 and then the engine shifts to S112.

After the ascending / descending operation (descending operation or ascending operation) is started in S112, it is determined in S128 whether the cab is changed, and if the cab is not changed, the ascending / descending operation is stopped in S129. After that, in S130, it is determined whether or not the running height is reached, and if it is not the running height, the ascending / descending operation ends in S131. After that, it shifts to S103.

When it is determined in S130 that the running height is high, it is determined in S132 whether the load is heavy, and when it is not heavy load, the process shifts to S131. When it is determined in S132 that the load is heavy, the second engine 4b is automatically driven in S133 and then shifts to S131.

When the driver's cab is changed in S128, the determination as to whether the elevating operation is in progress is repeated in S134. When it is determined in S134 that it is not in the middle of the ascending / descending operation, the process proceeds to S103.

The operation of the third energy saving mode will be described with reference to FIG. 7.

When the power of the transport vehicle 1 is turned on in S201, it is determined in S202 whether the third energy saving mode is selected. In S202, when the energy saving mode is not selected, the normal mode operation is performed. When it is determined in S202 that the third energy saving mode is selected, the driver's cab is selected in S203. Hereinafter, the operation when the first cab 10a is selected will be described. In S203, the operation when the second cab 10b is selected is the same as the operation when the first cab is selected, and thus the description thereof will be omitted.

When the first cab 10a is selected in S203, it is determined in S204 whether the first engine is being driven. When the first engine is being driven, it is determined in S205 whether the second engine 4b is being driven. When the second engine 4b is not driven in S205, it is determined in S206 whether the running height is reached. When it is determined in S206 that the running height is not high, the second engine 4b is automatically driven in S207. After that, when an instruction for ascending / descending operation is given in S208, it is determined in S209 whether the second engine is being driven, and when the second engine 4b is being driven, in S210, the first engine 4a and the second engine are second. It is confirmed that the engine 4b is driven, and the ascending / descending operation is started in S211.

When the first engine 4a is not driven in S204, it is determined in S212 whether the second engine 4b is driven. In S212, when the second engine 4b is not driven, it is determined in S213 whether it is the running height, and when it is not the running height, in S214, after the first engine 4a is automatically driven, after that, Move to S205.

When the second engine is driven in S212, the first engine 4a is automatically driven in S215. After that, in S216, it is determined whether or not the running height is reached, and if it is not the running height, the process shifts to S208. When it is determined in S216 that the running height is high, it is determined in S217 whether the load is heavy, and when it is not heavy load, the second engine 4b is automatically stopped in S218. When it is determined in S217 that the load is heavy, the process shifts to S208.

When it is determined in S213 that the running height is high, it is determined in S219 whether the load is heavy, and when the load is not heavy, the second engine 4b cannot be driven in S220 and shifts to S214. When it is determined in S219 that the load is heavy, the process shifts to S214.

In S205, when the second engine 4b is driven, the process shifts to S216.

When it is determined in S206 that the running height is high, it is determined in S221 whether the load is heavy, and when it is not heavy load, the second engine 4b is driven in S222 and shifts to S208. When it is determined in S221 that the load is heavy, the process proceeds to S207.

When the second engine 4b is not driven in S209, the second engine 4b is automatically driven in S224 and then shifts to S210.

After the ascending / descending operation is started in S211th, it is determined in S225 whether the cab is changed, and if the cab is not changed, the ascending / descending operation is stopped in S226. After that, in S227, it is determined whether or not the running height is reached, and if it is not the running height, the process proceeds to S203.

When it is determined in S227 that the running height is high, it is determined in S228 whether the load is heavy, and when it is not heavy load, the second engine 4b is automatically stopped in S229. When it is determined in S228 that the load is heavy, the process shifts to S203. When the driver's cab is changed in S225, the process shifts to S203.

In the transport vehicle 1, the amount of oil detected by the first detection sensor T1 arranged in the first tank 5a and the amount of oil detected by the second detection sensor T2 arranged in the second tank 5b are based on the amount of oil detected. By sending oil from one of the first tank 5a and the second tank 5b to the other, the imbalance between the amount of oil in the first tank 5a and the amount of oil in the second tank 5b is eliminated.

In the present embodiment, as shown in FIG. 8, the first tank 5a and the second tank 5b have an upper limit amount, a predetermined range set between the upper limit amount and the lower limit amount, and a lower limit amount, respectively. Set. The upper limit is to prevent the amount of oil in the tank from increasing and overflowing. The predetermined range and the lower limit amount are for eliminating the imbalance between the amount of oil in the first tank 5a and the amount of oil in the second tank 5b.

FIG. 8A shows the amount of oil in the tank when the loading platform 2 has the upper limit height, the running height, and the lower limit height in the normal mode. In the normal mode, the amount of oil in the first tank 5a and the amount of oil in the second tank 5b are the same. FIG. 8B shows the amount of oil in the tank when the loading platform 2 is the upper limit height, the running height, and the lower limit height when only the first engine 4a is driven in the energy saving mode. Since only the first engine 4a is driven, the amount of oil in the first tank 5a decreases, but the amount of oil in the second tank does not decrease.

In the normal mode, the upper limit amount d1, the predetermined range d2, and the lower limit amount d3 are set as shown in FIG. 8A, and in the energy saving mode, as shown in FIG. 8B, the upper limit amount d1', A predetermined range d2'and a lower limit amount d3' are set.

Therefore, in the normal mode, when either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b becomes the upper limit amount d1 or more, the tank having the upper limit amount d1 or more is transferred to the other tank. Oil is sent. In the energy saving mode, when either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b becomes the upper limit amount d1'or more, the tank having the upper limit amount d1'or more becomes the other tank. Oil is sent.

In the normal mode, when either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b exceeds the predetermined range d2 set between the upper limit amount d1 and the lower limit amount d3, the predetermined range When oil is sent from the tank exceeding d2 to the other tank and either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b becomes less than the predetermined range d2, it is less than the predetermined range d2. Oil is sent from the other tank to the tank that has become. In the energy saving mode, when either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b exceeds the predetermined range d2'set between the upper limit amount d1'and the lower limit amount d3'. When oil is sent from the tank exceeding the predetermined range d2'to the other tank, and either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b becomes less than the predetermined range d2'. Oil is sent from the other tank to the tank having a predetermined range d2'. In FIG. 8B, in the energy saving mode, the amount of oil in the second tank 5b at the traveling height exceeds the predetermined range d2', but only the first engine 4a is driven. Since the amount of oil in the second tank 5b does not decrease, no oil is sent from the second tank 5b to the first tank 5a.

In the normal mode, when the amount of oil in the first tank 5a and the amount of oil in the second tank 5b are equal to or less than the lower limit amount d3, oil is sent from the other tank to the tank having the lower limit amount d3 or less. In the energy saving mode, when the amount of oil in the first tank 5a and the amount of oil in the second tank 5b are equal to or less than the lower limit amount d3', oil is sent from the other tank to the tank having the lower limit amount d3' or less. Will be.

As shown in FIG. 8, regarding the upper limit amount of the first tank 5a and the second tank 5b, the upper limit amount d1 in the normal mode and the upper limit amount d1'in the energy saving mode are the same.

Regarding the oil amount in the predetermined range of the first tank 5a and the second tank 5b, the oil amount d2'in the predetermined range in the energy saving mode is smaller than the oil amount d2 in the predetermined range in the normal mode.

Regarding the lower limit amount of the first tank 5a and the second tank 5b, the lower limit amount d3'in the energy saving mode is smaller than the lower limit amount d3 in the normal mode.

In the present embodiment, when only one of the first engine 4a and the second engine 4b is driven in the energy saving mode, the amount of oil in the first tank 5a and the amount of oil in the second tank 5b are unbalanced. To solve the problem, it is conceivable to send oil from the engine tank on the drive side to the tank of the engine on the stop side, or to send oil from the tank of the engine on the stop side to the tank of the engine on the drive side.

For example, when oil is sent from the first tank 5a on the first engine 4a side to the second tank 5b on the second engine 4b side in a state where only the first engine 4a is being driven, the switching valve C4b of the hydraulic circuit 11cb is used. Is switched to a state in which the first hydraulic circuit 11a and the second hydraulic circuit 11b are communicated with each other, and the switching valve C4c of the hydraulic circuit 11cc is switched to a state in which the first hydraulic circuit circuit 11a and the second hydraulic circuit 11b are not communicated with each other. Will be.

For example, when oil is sent from the second tank 5b on the second engine 4b side to the first tank 5a on the first engine 4a side in a state where only the first engine 4a is being driven, the switching valve C4b of the hydraulic circuit 11cb is used. Is switched to a state in which the first hydraulic circuit 11a and the second hydraulic circuit 11b are not communicated with each other, and the switching valve C4c of the hydraulic circuit 11cc is switched to a state in which the first hydraulic circuit circuit 11a and the second hydraulic circuit circuit 11b are communicated with each other. Will be.

In the transport vehicle 1 of the present embodiment, when only one of the first engine 4a and the second engine 4b is driven, the first hydraulic circuit 11a and the second hydraulic circuit 11b are switched to a state of communication and driven. Since only the oil in the tank on the engine side is sent to the first cylinders a1-a6 and the second cylinders a7-a12, the amount of oil in the first tank 5a and the amount of oil in the second tank 5b become unbalanced. .. At this time, the amount of oil in the first tank 5a and the amount of oil in the second tank 5b are sent from the tank having the larger amount of oil in the first tank 5a and the second tank 5b to the tank having the smaller amount of oil. Can eliminate the imbalance of.

In the transport vehicle 1 of the present embodiment, when only one of the first engine 4a and the second engine 4b is driven, the switching valve C4a is in a communicating state to send oil from the drive side tank to the stop side tank. At the same time, by setting the switching valve C4a in a communicating state, oil can be sent from the stop side tank to the drive side tank. Therefore, when only one of the first engine 4a and the second engine 4b is driven, the loading platform can be raised and lowered.

In the transport vehicle 1 of the present embodiment, when either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b exceeds the upper limit, the tank that exceeds the upper limit becomes the other tank. Oil is sent to. Therefore, when the amount of oil in the tank exceeds the upper limit, it is possible to prevent the oil from overflowing.

In the transport vehicle 1 of the present embodiment, when either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b exceeds a predetermined range set between the upper limit amount and the lower limit amount, When oil is sent from the tank exceeding the predetermined range to the other tank and either the amount of oil in the first tank 5a or the amount of oil in the second tank 5b becomes less than the predetermined range, the oil falls below the predetermined range. Oil is sent from the other tank to the old tank. Therefore, the imbalance can be eliminated by the time the amount of oil in the first tank and the amount of oil in the second tank increase to the upper limit.

In the transport vehicle 1 of the present embodiment, the amount of oil in a predetermined range when only one of the first engine 4a and the second engine 4b is driven is a predetermined amount when the first engine 4a and the second engine 4b are driven. Less than the amount of oil in the range. Therefore, if the amount of oil in each predetermined range is the same, only one of the first engine 4a and the second engine 4b is driven to raise the loading platform 2 and then lower it, the oil is driven. It is returned to the tank of the engine on the side, but when the amount of oil in the tank reaches the upper limit, it is necessary to interrupt the lowering of the loading platform and eliminate the imbalance of the amount of oil in the tank, so the operating rate of lowering the loading platform Can be suppressed from decreasing.

In the transport vehicle 1 of the present embodiment, when the amount of oil in the first tank 5a and the amount of oil in the second tank 5b are equal to or less than the lower limit, oil is discharged from the other tank to the tank having the lower limit or less. Sent. Therefore, the imbalance between the amount of oil in the first tank and the amount of oil in the second tank can be eliminated.

In the transport vehicle 1 of the present embodiment, the lower limit amount when only one of the first engine 4a and the second engine 4b is driven is smaller than the lower limit amount when the first engine 4a and the second engine 4b are driven. .. Therefore, if the lower limit of each is the same, when only one of the first engine 4a and the second engine 4b is driven to raise the loading platform 2 and then lower it, the oil is the engine on the driving side. However, when the amount of oil in the tank reaches the upper limit, it is necessary to interrupt the lowering of the loading platform and eliminate the imbalance in the amount of oil in the tank, which reduces the operating rate of lowering the loading platform. Can be suppressed.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as it is described in the claims. Is.

In the above-described embodiment, a state in which the loading platform 2 is at the traveling height and there is no heavy object on the loading platform 2 is a light load state, and a state in which the loading platform 2 is at the traveling height and there is a heavy object on the loading platform 2. The heavy load state is set, but the state where the loading platform 2 is the traveling height and the weight of the heavy object on the loading platform 2 is a predetermined weight or less is the light load state, and the loading platform 2 is the traveling height and is on the loading platform 2. A state in which the weight of a heavy object exceeds a predetermined weight may be a heavy load state. In the above-described embodiment, the first hydraulic device and the second hydraulic device are cylinders for raising and lowering the loading platform 2, but in the present invention, the first hydraulic device and the second hydraulic device are limited to cylinders for raising and lowering the loading platform 2. No. Therefore, the first hydraulic device and the second hydraulic device may be motors for driving the traveling device.

1 Transport vehicle 2 Loading platform 3 Body A1-A12 Traveling device A1-A6 1st traveling device A7-A12 1st traveling device 4a 1st engine 4b 2nd engine a1-a12 Cylinder a1-a6 1st cylinder a7-a12 2nd cylinder 11a 1st hydraulic circuit 11b 2nd hydraulic circuit 12a 1st pump 12b 2nd pump C4a, C4b, C4c switching valve

Claims (7)

A vehicle body including a loading platform and multiple traveling devices,
The first hydraulic circuit to which the first tank and the first hydraulic device are connected,
A second hydraulic circuit to which the second tank and the second hydraulic device are connected,
The first engine that drives the first pump arranged in the first hydraulic circuit,
The second engine that drives the second pump arranged in the second hydraulic circuit,
The first detecting means for detecting the amount of oil in the first tank and
The second detecting means for detecting the amount of oil in the second tank and
The first tank and the second tank are based on the amount of oil in the first tank detected by the first detection means and the amount of oil in the second tank detected by the second detection means. A control unit that controls the first hydraulic circuit, the second hydraulic circuit, the first engine, and the second engine so that oil is sent from one tank to the other tank .
A first switching means for switching between a communicating state in which a portion downstream of the first pump of the first hydraulic circuit and a portion downstream of the second pump of the second hydraulic circuit are communicated and a non-communication state in which communication is not performed. ,
A second switch to switch between a communicating state in which the upstream portion of the first hydraulic circuit from the first pump and the upstream portion of the second hydraulic circuit from the second pump are communicated with each other and a non-communication state in which the second hydraulic circuit is not communicated. A transport vehicle characterized by having means. Equipped with multiple cylinders for raising and lowering the loading platform
The first hydraulic device is a first cylinder which is included in the plurality of cylinders, the second hydraulic device, according to claim 1, characterized in that a second cylinder which is included in the plurality of cylinders The carrier described. In the control unit, either the amount of oil in the first tank detected by the first detection means or the amount of oil in the second tank detected by the second detection means is equal to or higher than the upper limit amount. When the amount of oil exceeds the upper limit, the first hydraulic circuit, the second hydraulic circuit, the first engine, and the second engine are controlled so that oil is sent from the tank to the other tank. The transport vehicle according to claim 1 or 2, which is characterized by this. In the control unit, either the amount of oil in the first tank detected by the first detection means or the amount of oil in the second tank detected by the second detection means is the upper limit amount. When the predetermined range set between the upper limit and the lower limit is exceeded, oil is sent from the tank exceeding the predetermined range to the other tank, and the first tank is detected by the first detection means. When either the amount of oil in the oil or the amount of oil in the second tank detected by the second detection means is less than the predetermined range, the other tank is placed in the tank that is less than the predetermined range. The transport vehicle according to claim 3 , wherein the first hydraulic circuit, the second hydraulic circuit, the first engine, and the second engine are controlled so that oil is sent from the tank. The first engine drive state in which the first engine is driven and the second engine is not driven,
The second engine drive state in which the second engine is driven and the first engine is not driven,
It is possible to take a third engine drive state in which the first engine is driven and the second engine is driven.
The oil amount in the predetermined range for the first tank in the first engine drive state and the oil amount in the predetermined range for the second tank in the second engine drive state are the oil amounts in the third engine drive state. The transport vehicle according to claim 4 , wherein the amount of oil in the first tank and the second tank is less than the predetermined range of oil. In the control unit, either the amount of oil in the first tank detected by the first detection means or the amount of oil in the second tank detected by the second detection means is equal to or less than the lower limit. It is necessary to control the first hydraulic circuit, the second hydraulic circuit, the first engine and the second engine so that oil is sent from the other tank to the tank having the lower limit or less. The carrier according to any one of claims 1-5. The first engine drive state in which the first engine is driven and the second engine is not driven,
The second engine drive state in which the second engine is driven and the first engine is not driven,
It is possible to take a third engine drive state in which the first engine is driven and the second engine is driven.
The lower limit amount for the first tank in the first engine drive state and the lower limit amount for the second tank in the second engine drive state are the first tank and the first tank in the third engine drive state. The transport vehicle according to claim 6 , wherein the amount is less than the above lower limit for the second tank.

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