Electrical component

Abstract

To prevent freezing of electrical component contacts with a simple configuration.SOLUTION: A battery relay 1, which is an electrical component of a work machine, includes a movable contact 4 housed in a case 2, a contact-side terminal 5 which is a fixed contact housed in the case 2 and partially exposed to the outside of the case 2, a harness 6 which is arranged outside the case 2 and electrically connected to at least one of the contact-side terminal 5 or an excitation-side terminal 7, and a heat storage material 8. The heat storage material 8 is attached to the harness 6.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to electrical components of a working machine.

Background Art

[0002] Conventionally, when starting or stopping a vehicle, a relay is used to supply or cut off power to electronic devices and power supply devices mounted on the vehicle. For example, when operating a relay in a low-temperature environment below freezing, in order to prevent the contacts of the relay from freezing, techniques for preventing the contacts from freezing are known, such as changing the drive pattern of the relay or adding a temperature control device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the techniques described in Patent Documents 1 and 2, electronic components such as a control device for controlling the relay and a sensor for measuring the temperature are required.

[0005] An object of the present disclosure is to prevent freezing of the contacts of electrical components with a simple configuration.

Means for Solving the Problems

[0006] The electrical component of the working machine according to the present disclosure includes a movable contact housed in a case, a fixed contact housed in the case with a part thereof exposed outside the case, a wire disposed outside the case and electrically connected to at least one of the fixed contact or the movable contact, and a heat storage material. The heat storage material is attached to the wire.

Advantages of the Invention

[0007] According to the present disclosure, freezing of the contacts of electrical components can be prevented with a simple configuration.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. Also, some components may not be used.

[0010] In the embodiment, as an example of a working machine, a hydraulic excavator will be described, but the present disclosure is applicable to other working machines such as forklifts, wheel loaders, bulldozers, dump trucks, etc. in addition to hydraulic excavators.

[0011] [Embodiment] <Working Machine> FIG. 1 is a side view schematically showing the configuration of a working machine according to an embodiment. As shown in FIG. 1, the working machine 100 in the embodiment is, for example, a hydraulic excavator.

[0012] The working machine 100 includes a vehicle body 102 and a working device 104. The working device 104 is operably attached to the vehicle body 102. The working device 104 is driven by, for example, a hydraulic cylinder.

[0013] The vehicle body 102 includes a machine room 110. The machine room 110 is configured to form a space for accommodating an auxiliary battery 120 and a power source 130.

[0014] The auxiliary battery 120 supplies power to electrical devices mounted on the working machine 100 including, for example, a controller (not shown). In the embodiment, the auxiliary battery 120 is disposed inside the machine room 110.

[0015] The power source 130 supplies power required for driving the working machine 100. The power source 130 is, for example, an engine, a fuel cell, a hydraulic pump, or a high-voltage drive battery different from the auxiliary battery 120. The power source 130 is disposed inside the machine room 110. In the embodiment, the power source 130 is disposed adjacent to the auxiliary battery 120.

[0016] <Battery relay> With reference to FIGS. 2 and 3, an example of the configuration of a battery relay as an electrical component will be described. FIG. 2 is a perspective view of the battery relay according to the embodiment. FIG. 3 is a schematic diagram showing the configuration of the battery relay according to the embodiment.

[0017] The battery relay 1 is disposed inside the machine room 110. In the embodiment, the battery relay 1 is disposed adjacent to the auxiliary battery 120 (see FIG. 1). The battery relay 1 houses a coil 3 and a movable contact 4 in a case 2. A part of the contact-side terminal (fixed contact) 5 and a part of the exciting-side terminal 7 are exposed outside the case 2. A harness (electric wire) 6 is connected to the contact-side terminal 5.

[0018] The movable contact 4 moves relative to the contact-side terminal 5 which is a fixed contact. The movable contact 4 moves by the action of the coil 3. When the movable contact 4 and the contact-side terminal 5 come into contact, they are electrically connected. When the working machine 100 is in an operating state (i.e., when the key is on), the movable contact 4 comes into contact with the contact-side terminal 5 and is electrically connected. When the working machine 100 is in a non-operating state (i.e., when the key is off), the movable contact 4 separates from the contact-side terminal 5.

[0019] The contact-side terminal 5 which is a fixed contact is housed in the case 2 and a part thereof is exposed outside the case 2. The contact-side terminal 5 includes a fixed contact terminal 50 and a fixed contact fastening member 51.

[0020] The fixed contact terminal 50 is exposed outside the case 2. The fixed contact terminal 50 is fastened by the fixed contact fastening member 51 and is electrically connected. The fixed contact terminal 50 is electrically connected to the harness 6 via the harness terminal 60 and the harness fastening member 61 of the harness 6.

[0021] One axial side of the fixed contact fastening member 51 is housed in the case 2 and the other side is exposed outside the case 2. The fixed contact fastening member 51 is disposed across the inside and the outside of the case 2. The portion of the fixed contact fastening member 51 exposed outside the case 2 is fastened in a state of being in contact with the fixed contact terminal 50.

[0022] The harness 6 is a battery cable that electrically connects the auxiliary battery 120 and the battery relay 1. The harness 6 has a conductive material coated with an insulating member. The harness 6 is electrically connected to the contact-side terminal 5 via a harness terminal 60 and a harness fastening member 61. The harness terminal 60 and the fixed contact terminal 50 are overlapped and fastened by the harness fastening member 61.

[0023] The exciting-side terminal 7 is electrically connected to the coil 3.

[0024] <Heat storage material> The heat storage material 8 is attached to the outer periphery of the harness 6. The heat storage material 8 is for preventing the freezing of the contact-side terminal 5 which is the fixed contact of the battery relay 1. The heat storage material 8 stores heat by the heat inside the machine room 110 when the working machine 100 is in an operating state. The heat storage material 8 stores heat, for example, by the heat released from the power source 130 or the coil 3 when the working machine 100 is in an operating state. When the working machine 100 transitions from an operating state to a non-operating state and then the harness 6 and the ambient temperature become lower than the temperature of the heat storage material 8, the heat storage material 8 releases the stored heat to keep the harness 6 warm.

[0025] The heat storage material 8 is formed in a cylindrical shape, for example. The heat storage material 8 includes a main body 81 and a groove 82. The main body 81 is formed in a cylindrical shape. A groove 82 is formed in the main body 81 along the axial direction. The groove 82 is formed over the entire axial length of the main body 81. When attaching the heat storage material 8 to the harness 6, the harness 6 is accommodated in the space of the main body 81 from the groove 82. Due to the formation of the groove 82, the axial cross-section of the main body 81 has a C-shaped configuration.

[0026] The heat storage material 8 is disposed at a position closer to the harness terminal 60 of the harness 6. In other words, the heat storage material 8 is disposed at a position closer to the contact-side terminal 5 in the harness 6.

[0027] The heat storage material 8 is formed of a material that undergoes a phase change within the temperature range between the operating state and the non-operating state of the working machine 100. The heat storage material 8 is formed of a material that undergoes a phase change, for example, within a predetermined temperature range, such as around 20°C or more and 30°C or less. The heat storage material 8 maintains the temperature before and after the phase change for a certain period of time. The heat storage material 8 uses a material that undergoes a phase change within the above-described temperature range and maintains a constant temperature. For this reason, the temperature of the heat storage material 8 changes following the ambient temperature such as the outside air temperature in other temperature ranges.

[0028] The predetermined temperature range in which the heat storage material 8 undergoes a phase change may be set, for example, with an upper limit of a temperature about 10°C lower than the assumed ambient temperature near the battery relay 1 during the operation of the working machine 100 in a cold region. The predetermined temperature range in which the heat storage material 8 undergoes a phase change may be set, for example, with a lower limit of a temperature higher than 0°C at which moisture freezes.

[0029] <Function> With reference to FIG. 4, the function of the heat storage material 8 in the battery relay 1 will be described. FIG. 4 is a schematic diagram for explaining the function of the battery relay according to the embodiment. In the embodiment, the heat storage material 8 will be described assuming that a material that undergoes a phase change at a temperature of about 20°C or more and 30°C or less is used.

[0030] FIG. 4(a) shows the state of the battery relay 1 when the working machine 100 is in an operating state (that is, when the key is off). Due to the heat released from the power source 130 (see FIG. 1) and the coil 3, the peripheral region A1 centered on the case 2 and the peripheral region A2 of the harness 6 become high in temperature. The peripheral region A1 and the peripheral region A2 become higher in temperature than the predetermined temperature range in which the heat storage material 8 undergoes a phase change. When the peripheral region A1 centered on the case 2 becomes high in temperature, the temperature inside the case 2 rises, and the moisture 200 inside the case 2 is warmed and becomes water vapor. Also, when the peripheral region A2 of the harness 6 becomes high in temperature, the heat storage material 8 absorbs heat and accumulates thermal energy.

[0031] Figure 4(b) shows the state of the battery relay 1 when the working machine 100 transitions from the operating state to the non-operating state (i.e., when transitioning from key-on to key-off). Immediately after the working machine 100 transitions from the operating state to the non-operating state, the temperature inside the case 2 and the temperature of the harness 6 are maintained at a high temperature. When the working machine 100 enters the non-operating state, the temperature of the peripheral area A1 centered on the case 2 and the peripheral area A2 of the harness 6 gradually decreases according to the outside air temperature. Since the temperature of the peripheral area A1 centered on the case 2 drops faster than the temperature inside the case 2, a temperature difference occurs on the wall surface of the case 2. As a result, the moisture 200 inside the case 2 adheres to the wall surface of the case 2, and the wall surface of the case 2 condenses.

[0032] On the other hand, the temperature of the harness 6 drops faster than the temperature inside the case 2 by dissipating the absorbed heat to the outside air. However, since the harness 6 is maintained at a constant temperature and insulated by the heat storage material 8, the temperature of the contact-side terminal 5 via the harness 6 drops slower than the temperature inside the case 2. This suppresses the occurrence of a temperature difference between the contact-side terminal 5 and the inside of the case 2, thereby suppressing condensation on the contact-side terminal 5.

[0033] Figure 4(c) shows the state of the battery relay 1 when a certain period of time has elapsed after the working machine 100 transitions from the operating state to the non-operating state. The temperature of the peripheral area A1 centered on the case 2 and the peripheral area A2 of the harness 6 drops from the high temperature state to approximately equal to the outside air temperature. For this reason, when the outside air temperature is below freezing, the inside of the case 2 is rapidly cooled, and the moisture 200 adhering to the wall surface of the case 2 freezes. On the other hand, freezing of the contact-side terminal 5 is prevented by the moisture 200.

[0034] When the working machine 100 is in the operating state after Figure 4(c), even if the outside air temperature is below freezing, the surface of the contact-side terminal 5 is not frozen. As a result, the battery relay 1 can be electrically connected with the movable contact 4 and the contact-side terminal 5 in good contact.

[0035] <Effect> As described above, in the embodiment, the heat storage material 8 formed from a material that changes phase within a predetermined temperature range is attached to the outer periphery of the harness 6. According to the embodiment, the heat storage material 8 can prevent freezing of the contact side terminal 5 of the battery relay 1 by utilizing heat generated by the vehicle body when the work machine 100 is in an operating state. According to the embodiment, by using the heat storage material 8, it is possible to suppress temperature changes in the contact side terminal 5 of the battery relay 1 when the work machine 100 is not in an operating state. According to the embodiment, it is possible to prevent freezing of the contacts of the battery relay 1 with a simple configuration, without changing the electric circuit or electric control in order to prevent freezing of the contacts.

[0036] In this embodiment, the heat storage material 8 is maintained at a predetermined temperature range without using a heater, etc. As a result, the embodiment can suppress a reduction in the life span of the resin parts constituting the battery relay 1 and the auxiliary battery 120 located near the battery relay 1 due to the heat influence.

[0037] In the embodiment, in a temperature range other than the phase change temperature, the temperature of the heat storage material 8 changes in accordance with the ambient temperature of the battery relay 1. According to the embodiment, unlike a heat insulating material, the heat storage material 8 can provide unintentional heat insulation and prevent excessive temperature rises even when the work machine 100 is operated at a work site where the temperature becomes high.

[0038] The embodiment does not require electronic components for preventing freezing, such as a control device for controlling the battery relay 1 or a sensor for measuring temperature. According to the embodiment, it is possible to prevent freezing of the contacts of the battery relay 1 with a simple configuration, without changing the electric circuit or electric control in order to prevent freezing of the contacts.

[0039] In the embodiment, an electric circuit is not used to suppress temperature changes in the battery relay 1, so there is no need to apply voltage to the battery relay 1 after the key switch is turned off. According to the embodiment, after the key switch is turned off, the ambient temperature of the battery relay 1 reaches a temperature that causes the heat storage material 8 to undergo a phase change, thereby preventing the contacts of the battery relay 1 from freezing.

[0040] In the embodiment, since the heat storage material 8 is attached to the outer periphery of the electrically insulated harness 6, the work during the maintenance of the working machine 100 can be simplified.

[0041] According to the embodiment, the heat storage capacity can be adjusted by changing the shape such as the range where the heat storage material 8 is attached and the thickness of the heat storage material 8. The embodiment can be adapted to various working machines by appropriately changing the shape of the heat storage material 8.

[0042] The embodiment can be easily combined with other anti-freezing measures. When used in combination with a heater, the power consumption and heating time of the heater can be reduced in the embodiment.

[0043] [Modification Example 1] FIG. 5 is a perspective view of Modification Example 1 of the heat storage material. The heat storage material 8 includes a main body 81 formed in a spiral shape. The heat storage material 8 is formed of a flexible material. The heat storage material 8 is configured to be wound around the harness 6 by deforming the main body 81. The harness 6 can be accommodated in the space 83 of the main body 81.

[0044] [Modification Example 2] FIG. 6 is a perspective view of Modification Example 2 of the heat storage material. The heat storage material 8 is integrally formed with the terminal 52.

[0045] The terminal 52 is formed of a material having thermal conductivity. The heat of the fixed contact terminal 50 is transferred to the terminal 52. The terminal 52 is formed in an L shape. One wall portion of the terminal 52 is fastened by a fixed contact fastening member 51 in a state of being overlapped with the fixed contact terminal 50. The other wall portion of the terminal 52 is arranged along the side surface of the case 2. The heat storage material 8 is attached to the other wall portion of the terminal 52.

[0046] The heat storage material 8 is formed in a columnar shape. The other wall portion of the terminal 52 is inserted through the heat storage material 8 along the axial direction. The heat storage material 8 is arranged at a position closer to the fixed contact fastening member 51 in the terminal 52.

[0047] When the working machine 100 is in an operating state, the heat storage material 8 stores the heat of the fixed contact terminal 50 via the terminal 52. Immediately after the working machine 100 transitions from the operating state to the non-operating state, the heat storage material 8 maintains a constant temperature to keep the terminal 52 warm, so that the heat dissipation from the contact side terminal 5 via the terminal 52 is suppressed.

[0048] [Modification Example 3] FIG. 7 is a perspective view of Modification Example 3 of the heat storage material. In Modification Example 3, a fixed contact terminal 50a corresponding to the fixed contact terminal 50 of Modification Example 2 and a terminal 50b corresponding to the terminal 52 of Modification Example 2 are integrally formed. The heat storage material 8 is inserted into the terminal 50b. Thereby, the freezing of the contact of the battery relay 1 can be prevented with a simpler configuration compared to Modification Example 2.

[0049] <Other Modification Examples> In the above, the case of applying to the battery relay 1 of the working machine 100 has been described, but it is not limited thereto. For example, it may be an electromagnetic contactor or an electromagnetic switch, and it is applicable to electrical components for switching the power supply to the electrical equipment of the working machine. Thereby, for example, in a working machine operating in a cold region or the like, the freezing of the contacts of the electrical components can be prevented.

[0050] In the above, the heat storage material 8 has been described as being attached to the harness 6 attached to the fixed contact terminal 50 of the contact side terminal 5, but it is not limited thereto. The heat storage material 8 may be attached to a harness (not shown) attached to the exciting side terminal 7 on the movable contact 4 side. Thereby, the freezing of the movable contact 4 can be prevented.

[0051] Furthermore, the heat storage material 8 may be attached to both the harness 6 attached to the fixed contact terminal 50 of the contact side terminal 5 and the harness attached to the exciting side terminal 7. Thereby, the freezing of the contacts of the battery relay 1 can be more reliably prevented.

Explanation of Reference Numerals

[0052] 1... Battery relay, 2... Case, 3... Coil, 4... Movable contact, 5... Contact-side terminal (fixed contact), 50... Fixed contact terminal, 51... Fixed contact fastening member, 6... Harness (electric wire), 60... Harness terminal, 61... Harness fastening member, 7... Excitation-side terminal, 8... Heat storage material, 81... Main body, 82... Groove, 100... Working machine (hydraulic excavator), 102... Vehicle body, 104... Working machine, 110... Machine room, 120... Auxiliary machine battery, 130... Power source.

Claims

1. An electrical component for a working machine, comprising: a movable contact housed in a case; a fixed contact housed in the case and partially exposed outside the case; a wire disposed outside the case and electrically connected to at least one of the fixed contact or the movable contact; a heat storage material; and wherein the heat storage material is attached to the wire. The electrical component according to claim 1, wherein the heat storage material is formed of a material that undergoes a phase change in a predetermined temperature range.

2. The electrical component according to claim 1, wherein the heat storage material is attached to the wire electrically connected to the fixed contact.

3. The electrical component according to claim 1, wherein the heat storage material is disposed at a position on the wire where heat can be conducted to and from the fixed contact.

4. The electrical component according to claim 3, wherein the heat storage material is disposed at a position on the wire close to the fixed contact.

5. The electrical component according to claim 1, wherein the heat storage material is wound around the outer circumference of the wire.

6. The electrical component according to claim 1, wherein the heat storage material comprises a cylindrical body and a groove formed along the axial direction.

7. The electrical component according to claim 6, wherein the heat storage material is formed in a spiral shape.

8. An electrical component for a working machine, comprising: a movable contact housed in a case; a fixed contact housed in the case and partially exposed outside the case; a terminal disposed in contact with the fixed contact; a heat storage material; and wherein the heat storage material is attached to the terminal. The electrical component according to claim 8, wherein the heat storage material is formed of a material that undergoes a phase change in a predetermined temperature range.

9. An electrical component for a working machine, comprising: a movable contact housed in a case; a fixed contact housed in the case and partially exposed outside the case; a heat storage material; and wherein the fixed contact is integrally formed with a fixed contact terminal that contacts a wire and a terminal through which the heat storage material is inserted. The electrical component according to claim 9, wherein the heat storage material is formed of a material that undergoes a phase change in a predetermined temperature range.

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