Industrial vehicle

Abstract

To provide an industrial vehicle which can detect leakage of electrolytic solution of a lead-acid battery and prevent leakage of the electrolytic solution on floor surface (road surface).SOLUTION: An industrial vehicle comprises: a vehicle body 11; a battery case 30 which is mounted on the vehicle body 11 to accommodate a lead-acid battery; a liquid leakage detection device 56 which detects leakage of electrolytic solution of the lead-acid battery from the battery case 30; an annunciator which notifies leakage of the electrolytic solution; and a controller which is connected with the liquid leakage detection device 56 to control the annunciator. The vehicle body 11 includes a pair of support components supporting the battery case 30, the battery case 30 includes a drain hole 45, a liquid acceptor 50 is installed below the drain hole 45 and between the pair of support components, and the liquid leakage detection device 56 is equipped with the liquid acceptor 50.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This invention relates to industrial vehicles.

Background Art

[0002] As a conventional technology related to industrial vehicles, for example, an electrolytic solution leakage detection device disclosed in Patent Document 1 is known. The electrolytic solution leakage detection device disclosed in Patent Document 1 includes a battery mounted on an electric vehicle, a battery case that houses the battery, and a tray that constitutes the lower part of the battery case. A recess is provided at a position facing the lower surface of the battery in the tray. The recess opens so as to encompass the lower surface area of the battery and is recessed downward. A pH sensor is provided on the bottom surface of the recess. And the electrolytic solution leakage detection device includes a water holding part capable of holding water so as to be in contact with the pH sensor, and a first passage for supplying water to the water holding part. By detecting a change in the pH value based on the reaction between the electrolytic solution contained in the battery and the condensed water held in the water holding part with the pH sensor, leakage of the electrolytic solution from the battery is detected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the electrolyte leakage detection device reacts the electrolyte with the water supplied to the water holding part and detects the pH change due to this reaction with a pH sensor, it requires a pH sensor and also needs to supply water to the water holding part. Further, this type of technology is a technology for detecting leakage of an electrolyte such as lithium hexafluorophosphate when the target battery is mainly a lithium-ion battery, and is not applicable to detecting leakage of the electrolyte of a lead battery. By the way, in a lead battery, replenishing water to the battery is essential, but there is a risk of electrolyte leakage during this water replenishment operation. Also, when charging a lead battery, hydrogen is generated, and there is a risk that the liquid level of the electrolyte rises during charging and the electrolyte leaks. Since leakage of the electrolyte stains the floor surface, it is preferable to detect the leakage of the electrolyte at an early stage.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide an industrial vehicle that can detect leakage of the electrolyte of a lead battery and prevent leakage of the electrolyte onto the floor surface.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention provides an industrial vehicle having a vehicle body, a battery case mounted on the vehicle body for housing a lead battery, a liquid leakage detector for detecting leakage of the electrolyte of the lead battery from the battery case, and a controller connected to the liquid leakage detector for determining the occurrence of liquid leakage of the electrolyte. The vehicle body includes a pair of support members for supporting the battery case. The battery case has a drain hole, and a liquid receiver is installed below the drain hole and between the pair of supports. The liquid leakage detector is provided in the liquid receiver.

[0007] In the present invention, when the electrolyte leaks from the lead battery, the leaked electrolyte drops onto the liquid receiver through the drain hole of the battery case. The liquid receiver is installed between a pair of support members. When the liquid leakage detector installed on the liquid receiver detects the electrolyte, the controller determines that liquid leakage has occurred. The controller can detect the leakage of the electrolyte of the lead battery. Further, since the liquid receiver receives the leaked electrolyte, leakage of the electrolyte onto the floor surface (road surface) can be prevented. Furthermore, by installing the liquid receiver between a pair of support members, the liquid receiver can be installed below the battery case in a vehicle body with space constraints.

[0008] Also, in the above industrial vehicle, the liquid leakage detector may include an energizing portion that is energized by the electrolyte, and the controller may be configured to determine that liquid leakage has occurred when the energizing resistance value in the energizing portion changes. In this case, when the electrolyte in the liquid receiver interferes with the energizing portion, the energizing resistance value fluctuates, so the liquid leakage detector can surely detect the leakage of the electrolyte.

[0009] Also, in the above industrial vehicle, the energizing portion may be configured to be located below the drain hole. In this case, the electrolyte falling from the drain hole can interfere with the energizing portion, so the leakage of the electrolyte can be detected before the electrolyte is stored in the liquid receiver.

[0010] Also, in the above industrial vehicle, the liquid receiver may be configured to include a drain hose for discharging the electrolyte stored in the liquid receiver. In this case, since it is provided with a drain hose for discharging the electrolyte stored in the liquid receiver, the electrolyte stored in the liquid receiver can be drained through the drain hose. Since the electrolyte can be removed from the liquid receiver, it is possible to prevent the electrolyte from overflowing from the liquid receiver.

[0011] Also, in the above industrial vehicle, it may have a notifier for notifying liquid leakage of the electrolyte, and when the controller determines liquid leakage of the electrolyte, the controller may operate the notifier. In this case, when the controller determines that electrolyte leakage has occurred, the controller activates the alarm, enabling early notification to the surroundings that electrolyte leakage has occurred.

[0012] Further, in the above industrial vehicle, the liquid leakage detector may be configured as a water pressure sensor that detects the water pressure of the electrolyte stored in the liquid receiver. In this case, since the water pressure of the electrolyte stored in the liquid receiver is detected, electrolyte leakage can be reliably detected.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide an industrial vehicle that can detect leakage of the electrolyte of a lead battery and prevent leakage of the electrolyte onto the floor surface (road surface).

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0015] (First Embodiment) Hereinafter, a forklift as an industrial vehicle according to the first embodiment will be described with reference to the drawings. The forklift of this embodiment is a battery-powered forklift equipped with a battery. Regarding "front-rear", "left-right", and "up-down" for specifying directions, it is shown based on the state where the operator of the forklift is seated on the driver's seat of the driver's cab and facing the forward side of the forklift.

[0016] As shown in FIG. 1, front wheels 12 are provided at the front part of the vehicle body 11 of the forklift 10, and rear wheels 13 are provided at the rear part of the vehicle body 11. The front wheels 12 are drive wheels, and the rear wheels 13 are steering wheels. A traveling motor 14 for driving the front wheels 12 is mounted on the vehicle body 11. A counterweight 15 is provided at the rear part of the vehicle body 11. The counterweight 15 is for adjusting the vehicle weight and achieving weight balance in the vehicle body 11. A cargo handling device 16 is provided at the front part of the vehicle body 11.

[0017] The cargo handling device 16 includes a mast 17 having an outer mast 18 and an inner mast 19. As shown in FIG. 2, the cargo handling device 16 includes a lift bracket 20 that can move up and down along the inner mast 19. A pair of left and right forks 21 are locked to the lift bracket 20.

[0018] A tilt cylinder 22 that operates with hydraulic oil is installed between the vehicle body 11 and the cargo handling device 16. A lift cylinder 23 that operates by supplying and discharging hydraulic oil is provided on the outer mast 18 (see FIG. 1).

[0019] A driver's seat 24 is provided near the center of the vehicle body 11. The vehicle body 11 is provided with a head guard 25 that covers the upper part of the driver's seat 24. A seat stand 26 is provided in front of the counterweight 15 in the driver's seat 24 so as to be openable and closable. A driver's seat 27 is provided on the upper part of the seat stand 26. A removable or openable and closable toe board 28 is provided on the floor surface of the driver's seat 24. A battery case 30 is accommodated below the seat stand 26 and the toe board 28 in the vehicle body 11. When replacing the battery, the battery case 30 can be taken in and out of the vehicle body 11 by opening the toe board 28 together with the seat stand 26. Details of the battery case 30 and means for supporting the battery case 30 will be described later.

[0020] An instrument panel 29 is provided in front of the driver's seat 24. The instrument panel 29 is provided with a lift lever 33 and a tilt lever 34 as cargo handling levers.

[0021] As shown in FIG. 1, the vehicle body 11 is provided with a controller 35 that controls each part of the forklift 10. As shown in FIG. 3, the controller 35 includes a storage unit 37 composed of a CPU 36, a RAM, a ROM, etc. The controller 35 may be provided with dedicated hardware for executing at least a part of various processes, for example, an application specific integrated circuit (ASIC). The controller 35 can be configured as a circuit including one or more processors that operate according to a computer program, one or more dedicated hardware circuits such as an ASIC, or a combination thereof. The storage unit 37 stores program codes or instructions configured to cause the CPU 36 to execute processing. Various programs for controlling each part of the forklift 10 are stored in the storage unit 37.

[0022] Here, the means for supporting the battery case 30 will be described. As shown in FIGS. 4 and 5, the vehicle body 11 includes a bottom frame plate 38 that forms the bottom of the vehicle body 11, and a front support member 39 and a rear support member 40 as a pair of supports formed on the upper part of the bottom frame plate 38. The front support member 39 and the rear support member 40 support the battery case 30. The front support member 39 is provided on the front side of the bottom frame plate 38, and the rear support member 40 is provided on the rear side of the bottom frame plate 38. A gap is formed between the front support member 39 and the rear support member 40. In a state where the battery case 30 is supported by the front support member 39 and the rear support member 40, a space 41 including the gap is formed by the battery case 30, the bottom frame plate 38, the front support member 39, and the rear support member 40.

[0023] Next, the battery case 30 will be described. As shown in FIGS. 4 and 5, the battery case 30 is box-shaped and has a substantially rectangular bottom plate 42, a pair of first side plates 43 rising from the bottom plate 42, and a pair of second side plates 44. A drain hole 45 is formed in the bottom plate 42 of the battery case 30. The drain hole 45 is a through hole for discharging the leaked electrolyte when the electrolyte of the battery cell 46 described below leaks. In the present embodiment, it is formed at a position near the center in the left-right direction at the front of the bottom plate 42.

[0024] A plurality of battery cells 46 are accommodated in the battery case 30. In the present embodiment, 24 battery cells 46 are accommodated in the battery case 30. Note that they are accommodated such that the space between adjacent battery cells 46 is located above the drain hole 45 (see FIG. 5). The battery cell 46 is a rechargeable lead battery, and an electrode (not shown) is accommodated in the battery cell 46 and an electrolyte is injected.

[0025] On the upper surface of the battery cell 46, there are provided electrode terminals (not shown) and a liquid injection port 47 for water replenishment. The electrode terminals of each battery cell 46 are connected to adjacent terminals so that the battery cells 46 are electrically connected in series. As shown in FIG. 3, the forklift 10 has an automatic water replenishing device 48. The automatic water replenishing device 48 includes, in addition to a water replenishing pipe 49 connected to each battery cell 46, a water replenishing tank (not shown) and a water replenishing pump (not shown) for pumping up the water replenishing liquid from the water replenishing tank.

[0026] As shown in FIG. 4, the liquid injection port 47 is connected to the water replenishing pipe 49 provided in the automatic water replenishing device 48. The water replenishing pump is controlled by the controller 35. Further, the automatic water replenishing device 48 is provided with a liquid level sensor (not shown) for detecting the liquid level of the electrolyte in the battery cell 46, and when the liquid level drops below a certain level, the water replenishing liquid is automatically supplied from the water replenishing tank to the battery cell 46. Note that in FIG. 4, the illustration of some of the water replenishing pipes 49 is omitted, and in FIG. 5, the illustration of all the water replenishing pipes 49 is omitted.

[0027] The forklift 10 of the present embodiment is provided with a mechanism for detecting leakage of the electrolyte from the battery cell 46 and preventing the leaked electrolyte from falling onto the floor surface (road surface). In the space 41, a liquid receiver 50 is installed on the bottom frame plate 38 so as to be located below the drain hole 45. The liquid receiver 50 is a box-shaped body capable of receiving the leaked electrolyte and storing a certain amount. The liquid receiver 50 has a substantially rectangular bottom plate portion 51, side plate portions 52 rising from the outer edge of the bottom plate portion 51, and a pair of mounting portions 53. A drain hose 54 is connected to the bottom plate portion 51.

[0028] The drain hose 54 is a flexible hose for discharging the electrolyte retained in the liquid receptor 50, and an on-off valve 55 is provided at the tip of the drain hose 54. The drain hose 54 can be drawn out from a through hole 38A formed in the bottom frame plate 38. A liquid leakage detector 56 is provided on the side plate portion 52 that retains the electrolyte in the liquid receptor 50. Among the spaces 41, the spaces around the liquid receptor 50 and the liquid leakage detector 56 are spaces through which electrical wiring, hydraulic piping, etc. (not shown) pass, and are spaces subject to space constraints.

[0029] As shown in FIG. 6, the liquid leakage detector 56 has a main body portion 57 provided on the outer surface of the side plate portion 52 and a rod-shaped energizing portion 58 inserted into the liquid receptor 50. The main body portion 57 of the leakage detector 56 is electrically connected to the controller 35. The energizing portion 58 is composed of a pair of electrodes and is installed laterally from the side plate portion 52 so as to approach the bottom plate portion 51.

[0030] The energization resistance value in the energizing portion 58 is constant when the electrolyte does not interfere with the energizing portion 58, but varies when the electrolyte interferes with the energizing portion 58. For example, when the electrolyte is stored in the liquid receptor 50 and the energizing portion 58 is immersed in the electrolyte, a current flows through the energizing portion 58, and the energization resistance value surely varies. Also, the energization resistance value may vary even when the falling electrolyte wets the energizing portion 58. When a variation occurs in the energization resistance value of the energizing portion 58, the liquid leakage detector 56 transmits a signal indicating the variation in the energization resistance value of the energizing portion 58 to the controller 35. The controller 35 determines that the electrolyte is leaking upon receiving a signal indicating the variation in the energization resistance value of the energizing portion 58.

[0031] As shown in FIG. 3, a warning lamp 59 and a warning buzzer 60 as notification devices are connected to the controller 35. When the controller 35 determines that the electrolyte is leaking, it operates the warning lamp 59 and the warning buzzer 60, and also stops the automatic water replenishing device 48 if the automatic water replenishing device 48 is operating. The warning lamp 59 and the warning buzzer 60 are provided near the driver's seat 24 so that the operator of the forklift 10 can easily notice them.

[0032] Next, the detection of electrolyte leakage in the forklift 10 of the present embodiment will be described. First, the detection of electrolyte leakage during water replenishment by the automatic water replenishing device 48 will be described. When the liquid level of the battery cell 46 of the forklift 10 drops below a certain level, the controller 35 activates the automatic water replenishing device 48 to supply the replenishing liquid to each battery cell 46. At this time, the electrolyte may overflow from the battery cell 46 for some reason. Then, as shown in FIG. 7(a), when the overflowed electrolyte E leaks into the battery case 30, it drops through the drain hole 45 onto the liquid receiver 50 and is stored in the liquid receiver 50.

[0033] When the electrolyte E drops from the drain hole 45 and interferes with the energized portion 58 of the liquid leakage detector 56, the energization resistance value of the energized portion 58 fluctuates. A signal indicating the fluctuation of the energization resistance value of the energized portion 58 is transmitted to the controller 35. Even if the electrolyte does not interfere with the energized portion 58 when the electrolyte E drops, as shown in FIG. 7(b), if the liquid level of the electrolyte E stored in the liquid receiver 50 interferes with the energized portion 58, the energization resistance value fluctuates.

[0034] Upon receiving a signal indicating the fluctuation of the energization resistance value of the energized portion 58, the controller 35 activates the warning lamp 59 and the warning buzzer 60 and stops the automatic water replenishing device 48. The leakage of the electrolyte E from the battery cell 46 is notified to the surroundings by the lighting of the warning lamp 59 and the operation of the warning buzzer 60. The electrolyte E is stored in the liquid receiver 50, so that the electrolyte E does not drop onto the floor surface (road surface). The electrolyte E stored in the liquid receiver 50 may be, for example, transferred to another container by opening the on-off valve 55 of the drain hose 54 by the operator and disposed of.

[0035] Next, the detection of electrolyte leakage in the battery cell 46 during charging will be described. When the battery cell 46 is charged, hydrogen gas is generated in the battery cell 46, and the generated hydrogen gas may raise the liquid level of the electrolyte. When the liquid level of the electrolyte is raised by the hydrogen gas and the electrolyte overflows from the battery cell 46 and leaks into the battery case 30, it drops into the liquid receiver 50 through the drain hole 45, and is stored in the liquid receiver 50. When the electrolyte E interferes with the energized portion 58 of the liquid leakage detector 56, a signal indicating a change in the energization resistance value of the energized portion 58 is transmitted to the controller 35. The controller 35 receives a signal indicating a change in the energization resistance value of the energized portion 58, and activates the warning lamp 59 and the warning buzzer 60. The operator can recognize the leakage of the electrolyte E by the lighting of the warning lamp 59 and the operation of the warning buzzer 60, and can immediately stop the charging.

[0036] The forklift 10 of the present embodiment has the following effects. (1) When the electrolyte leaks from the battery cell 46, the leaked electrolyte E drops into the liquid receiver 50 through the drain hole 45 of the battery case 30. The liquid receiver 50 is installed between a pair of support members. When the liquid leakage detector 56 installed in the liquid receiver 50 detects the electrolyte E, the controller 35 can determine the occurrence of electrolyte leakage in the battery cell 46. Further, since the liquid receiver 50 receives the leaked electrolyte E, leakage of the electrolyte E onto the floor surface (road surface) can be prevented. Furthermore, by installing the liquid receiver 50 between a pair of support members, the liquid receiver 50 can be installed below the battery case 30 in the vehicle body 11 with space constraints.

[0037] (2) The liquid leakage detector 56 includes an energized portion 58 that is energized by the electrolyte E. The controller 35 determines that liquid leakage has occurred when the energization resistance value in the energized portion 58 changes. Therefore, when the electrolyte E in the liquid receiver 50 interferes with the energized portion 58, the energization resistance value fluctuates, so that the liquid leakage detector 56 can surely detect the leakage of the electrolyte E.

[0038] (3) The energizing part 58 is located below the drain hole 45. Since the electrolytic solution E falling from the drain hole 45 interferes with the energizing part 58, it is possible to detect leakage of the electrolytic solution E before the electrolytic solution E is stored in the liquid receiver 50.

[0039] (4) The liquid receiver 50 is provided with a drain hose 54 for discharging the electrolytic solution E stored in the liquid receiver 50. Therefore, the electrolytic solution E stored in the liquid receiver 50 can be drained through the drain hose 54. Since the electrolytic solution E can be removed from the liquid receiver 50, it is possible to prevent the electrolytic solution E from overflowing from the liquid receiver 50.

[0040] (5) Since it has a warning lamp 59 and a warning buzzer 60, when the liquid leakage detector 56 detects the electrolytic solution E, the controller 35 activates the warning lamp 59 and the warning buzzer 60 that notify of liquid leakage. By operating the warning lamp 59 and the warning buzzer 60, it is possible to quickly notify the surroundings of the leakage of the electrolytic solution from the battery cell 46.

[0041] (Second Embodiment) Next, the second embodiment will be described. In this embodiment, the configuration of the liquid leakage detector is different from that of the first embodiment. In this embodiment, for the same configuration as in the first embodiment, the description of the first embodiment is incorporated and common reference numerals are used.

[0042] As shown in FIG. 8(a), the forklift 70 has a liquid leakage detector 71. The liquid leakage detector 71 in this embodiment is a water pressure sensor that detects the water pressure of the electrolytic solution E stored in the liquid receiver 50. As shown in FIG. 8(b), the liquid leakage detector 71 has a main body part 72 provided on the lower surface of the bottom plate part 51 of the liquid receiver 50 and a water pressure sensor part 73 provided on the bottom plate part 51. When the electrolytic solution E is stored in the liquid receiver 50, the water pressure sensor part 73 detects the liquid pressure of the electrolytic solution E stored in the liquid receiver 50, and the controller 35 determines that the electrolytic solution E has leaked.

[0043] According to the present embodiment, since the liquid leakage detector 71 which is a water pressure sensor detects the water pressure of the electrolytic solution E stored in the liquid receiver 50, for example, it does not detect a small amount of condensed water falling from the battery case 30 as a leakage of the electrolytic solution E. That is, since it detects the water pressure of the electrolytic solution E stored in the liquid receiver 50, it can surely detect the leakage of the electrolytic solution E.

[0044] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the invention. For example, it may be modified as follows.

[0045] ○ In the above embodiment, an industrial vehicle equipped with an automatic water replenishing device has been described, but it is not limited thereto. For example, a forklift not equipped with an automatic water replenishing device may be used. In this case, in the operation where the operator replenishes the replenishing liquid, the leakage of the electrolytic solution can be detected and the fall of the electrolytic solution onto the floor surface can be prevented. ○ In the above embodiment, the energizing part of the liquid leakage detection part is installed so as to be located below the drain hole of the battery case, but it is not limited thereto. The energizing part may be installed, for example, at a position other than below the drain hole of the battery case. ○ In the above embodiment, it is assumed that the liquid receiver is provided with a drain hose for discharging the electrolytic solution stored in the liquid receiver, but it is not limited thereto. For example, when means for removing the electrolytic solution stored in the liquid receiver without overflowing is provided, the drain hose may not be provided. ○ In the above embodiment, an industrial vehicle having a warning device has been exemplified, but it is not limited thereto. For example, in the case of an industrial vehicle equipped with an automatic water replenishing device and not having a warning device, the automatic water replenishing device may be stopped immediately when the controller determines that liquid leakage has occurred. ○ In the above embodiment, a warning lamp and a warning buzzer have been exemplified and described as the warning device, but it is not limited thereto. The warning device may be, for example, a warning by character or graphic display, and any means capable of warning the surrounding area of the leakage of the electrolytic solution is acceptable. ○ In the above-described embodiment, a forklift as an industrial vehicle has been exemplified and described, but the present invention is not limited thereto. The industrial vehicle may be any industrial vehicle equipped with a lead battery, and in addition to a forklift, for example, a tractor, a towing tractor, or an automated guided vehicle may also be used.

Explanation of Signs

[0046] 10, 70 Forklift (Industrial Vehicle) 11 Vehicle Body 12 Front Wheel 13 Rear Wheel 14 Travel Motor 16 Loading and Unloading Device 21 Fork 24 Driver's Seat 30 Battery Case 35 Controller 38 Bottom Frame Plate 39 Front Support Member (Support) 40 Rear Support Member (Support) 41 Space 45 Drain Hole 46 Battery Cell 48 Automatic Water Supply Device 50 Liquid Receiver 54 Drain Hose 55 On - Off Valve 56, 71 Liquid Leakage Detector 57, 72 Main Body 58 Energizing Part 59 Warning Lamp (Notification Device) 60 Warning Buzzer (Notification Device) 73 Water Pressure Sensor Part E Electrolyte

Claims

1. A vehicle body, a battery case mounted on the vehicle body for accommodating a lead battery, a liquid leakage detector for detecting leakage of the electrolyte of the lead battery from the battery case, and a controller connected to the liquid leakage detector for determining the occurrence of electrolyte leakage. In an industrial vehicle having these components, the vehicle body includes a pair of support members for supporting the battery case, the battery case has a drain hole, a liquid receiver is installed below the drain hole and between the pair of supports, and the liquid leakage detector is provided in the liquid receiver. An industrial vehicle characterized by this.

2. The liquid leakage detector includes an energizing portion energized by the electrolyte, and the controller determines that liquid leakage has occurred when the energizing resistance value in the energizing portion changes. The industrial vehicle according to Claim 1, characterized by this.

3. The energizing portion is located below the drain hole. The industrial vehicle according to Claim 2, characterized by this.

4. The liquid receiver is provided with a drain hose for discharging the electrolyte stored in the liquid receiver. The industrial vehicle according to any one of Claims 1 to 3, characterized by this.

5. having an alarm for alarming electrolyte leakage, and when the controller determines electrolyte leakage, the controller operates the alarm. The industrial vehicle according to any one of Claims 1 to 3, characterized by this.

6. The liquid leakage detector is a water pressure sensor for detecting the water pressure of the electrolyte stored in the liquid receiver. The industrial vehicle according to Claim 1, characterized by this.

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