METHOD FOR MAKING A MOTOR VEHICLE DC-DC CONVERTER SAFE

Abstract

The invention relates to a method for securing a DC-DC converter (10) for a voltage measurement by means of a test apparatus (17) comprising: - a step of removing sealing plugs closing access openings to voltage measurement interfaces, - a step of placing measuring plugs (21.1, 21.2) inside the access openings to the voltage measurement interfaces, and - a step of inserting each measuring tip (18.1, 18.2) of the test apparatus (17) inside a through hole (22.1, 22.2) of a measuring tip made in a corresponding measuring plug (21.1, 21.2) to ensure the absence of voltage at the terminals of an electrical component electrically connected to the DC-DC converter (10). Figure 4

Description

Title of the invention: METHOD FOR MAKING A VEHICLE DC-DC CONVERTER SAFE CAR

[0001] The present invention relates to a method for securing a DC-DC converter of a motor vehicle. The invention finds a particularly advantageous application with vehicles using hydrogen for the production of electrical energy.

[0002] In a manner known per se, a fuel cell embedded in a motor vehicle powered by hydrogen makes it possible to produce electrical energy intended to power one or more electric traction motors. The fuel cell may be associated with an electric battery intended to store electrical energy generated by the fuel cell or by external recharging.

[0003] The fuel cell and the electric battery are electrically connected to each other via a DC / DC electrical converter (or direct / direct converter).

[0004] During an after-sales service intervention, it is necessary to take voltage measurements at the measurement interfaces arranged on the DC / DC converter in order to ensure that the voltage at the terminals of the fuel cell and the voltage at the terminals of the electric battery of the DC / DC converter are zero to make the intervention safe by avoiding any risk of electrocution.

[0005] The measurement interfaces are arranged inside a housing and accessible via through openings closed by sealing plugs to ensure the protection and sealing of the assembly. To carry out a voltage absence measurement, the operator therefore first removes the sealing plugs to access the measurement interfaces. The operator then inserts measuring tips of a voltage absence tester inside the access openings to the corresponding measurement interfaces of the fuel cell and then of the electric battery to ensure the absence of voltage at the terminals of these two electrical components.

[0006] However, given the large diameter of the access openings to the measurement interfaces, it is possible that an operator's finger could come into contact with an electrical potential of the DC / DC converter, which constitutes a safety risk that is unacceptable with regard to certain protection standards.

[0007] The invention aims to effectively remedy this safety problem by proposing a method for making a DC-DC converter safe for taking a voltage measurement by means of a test device comprising two measuring tips, said method comprising: - a step of removing sealing plugs closing access openings to voltage measurement interfaces, said access openings being made in a housing of the DC-DC converter, - a step of placing measuring plugs inside the access openings to the voltage measurement interface, the measuring plugs comprising a hole for the passage of a measuring tip of the test device, and - a step of inserting each measuring tip of the test device inside a measuring tip passage hole made in a corresponding measuring plug to ensure the absence of voltage at the terminals of an electrical component electrically connected to the DC-DC converter.

[0008] The invention thus makes it possible to avoid any risk of electrocution when handling the measuring tips of the test device to carry out voltage measurements at the terminals of the fuel cell or the electric battery. The invention also makes it possible to make the method for verifying the absence of voltage at the terminals of the fuel cell and the electric battery compliant with certain standards.

[0009] According to one implementation of the invention, said method comprises a step of verifying the absence of voltage at terminals of a fuel cell.

[0010] According to one implementation of the invention, said method comprises a step of verifying the absence of voltage at terminals of an electric battery.

[0011] According to one implementation of the invention, said method further comprises a step of removing the measuring plugs and a step of replacing the sealing plugs inside the access openings to the voltage measuring interfaces.

[0012] The invention also relates to an assembly for a motor vehicle comprising: - a DC-DC converter comprising terminals for connection to at least two electrical components, said DC-DC converter comprising at least two voltage measurement interfaces associated with an electrical component, and a housing in which at least two access openings to the voltage measurement interfaces are made, and - at least two measuring plugs intended to close the access openings to the voltage measuring interfaces, each measuring plug having a hole for the passage of a measuring tip of a test device.

[0013] According to one embodiment of the invention, each hole for the passage of a measuring tip has a maximum dimension substantially equal to a diameter of a measuring tip of a testing device.

[0014] According to one embodiment of the invention, each measuring plug comprises a tubular wall and an end wall comprising the hole for the passage of a tip of measure.

[0015] According to one embodiment of the invention, the tubular wall has a section complementary to that of an access opening to a voltage measurement interface.

[0016] According to one embodiment of the invention, each hole for the passage of a measuring tip has a diameter of less than 10 mm.

[0017] The invention further relates to a motor vehicle comprising an assembly as previously defined.

[0018] The invention will be better understood upon reading the following description and examining the accompanying figures. These figures are given only for illustrative purposes but in no way limit the invention.

[0019] [Fig-1] [Fig.l] is a schematic representation from above of a converter DC-DC comprising terminals for connection to a fuel cell and an electric battery as well as access openings to voltage measurement interfaces closed by sealing plugs;

[0020] [Fig.2] [Fig.2] is a schematic top view of the DC-DC converter of [Fig.l] after removal of the blanking plugs;

[0021] [Fig.3] [Fig.3] is a schematic top view of the DC-DC converter of [Fig.l] after the measuring plugs have been fitted;

[0022] [Fig.4] [Fig.4] is a perspective view illustrating a voltage measurement using a voltage absence tester having measuring tips inserted inside the measuring caps;

[0023] [Fig.5] [Fig.5] is a sectional view of a measuring cap according to the present invention.

[0024] Identical, similar, or analogous elements retain the same reference from one figure to another.

[0025] [Fig.l] shows a DC-DC converter 10 (DC / DC converter) comprising a housing 13 carrying connection terminals to at least two electrical components, in particular a fuel cell and an electric battery (not shown). For this purpose, the DC-DC converter 10 comprises two connection terminals 11.1, 11.2 to a fuel cell and two connection terminals 11.3, 11.4 to an electric battery. The converter 10 may also comprise end pieces 14.1 and 14.2 for connection to a cooling circuit, one of the end pieces 14.1, 14.2 corresponding to a coolant inlet and the other end piece 14.1, 14.2 corresponding to a coolant outlet.

[0026] The hydrogen-powered fuel cell makes it possible to produce electrical energy intended to power one or more electric traction motors. The electric battery is intended to store electrical energy generated by the fuel cell or by external recharging.

[0027] The converter 10 also comprises access openings 12.1-12.4 made in the housing 13 of the converter 10 and opening onto voltage measurement interfaces 15.1-15.4 visible in [Fig.2]. Each access opening 12.1-12.4 opens opposite a corresponding voltage measurement interface 15.1-15.4. The voltage measurement interfaces 15.1-15.4 are constituted for example by electrical tracks each electrically connected to an electrical potential of one of the electrical components.

[0028] Thus, a voltage measuring interface 15.1 is electrically connected to a positive electrical potential of the fuel cell and a voltage measuring interface 15.2 is electrically connected to a negative electrical potential of the fuel cell. A voltage measuring interface 15.3 is electrically connected to a positive electrical potential of the electric battery. A voltage measuring interface 15.4 is electrically connected to a negative electrical potential of the electric battery.

[0029] The access openings 12.1-12.4 are closed by sealing plugs 16.1-16.4 in order to ensure the sealing of the assembly. Each sealing plug 16.1-16.4 has a solid end wall located at one end of a tubular wall having a shape complementary to the access opening 12.1-12.4.

[0030] The method for securing the DC-DC converter 10 for taking a voltage measurement at the terminals of an electrical component is described below. The voltage measurement is carried out by means of a voltage absence tester 17 visible in [Fig. 4] comprising two measuring tips 18.1-18.2 connected to a module 19 integrating means for indicating, in particular visually and / or audibly, an absence or presence of voltage at the terminals of the measuring tips 18.1-18.2.

[0031] For this purpose, as shown in [Fig.2], the operator removes the sealing plugs 16.1-16.4 to access the voltage measurement interfaces 15.1-15.2.

[0032] As shown in [Fig. 3], the operator then has, in place of the sealing plugs 16.1-16.4, the measuring plugs 21.1-21.4 inside the access openings 12.1-12.4 to the voltage measuring interfaces 15.1-15.4.

[0033] Each measuring cap 21.1-21.4 comprises a passage hole 22.1-22.4 of a measuring tip having a larger dimension, in particular a diameter, substantially equal to a diameter of a measuring tip 18.1-18.2 of the test apparatus 17. The diameter of a passage hole 22.1-22.4 of a measuring tip is less than a diameter of an operator's finger. Preferably, the diameter is less than 10 mm and is of the order of 8 mm. By "of the order of" is meant a possible variation of plus or minus 10% compared to the indicated value. In this case, a passage hole 22.1-22.4 of a measuring tip has a round section but could alternatively have a rectangular, square, oval section or any other shape adapted to the passage of a measuring tip 18.1-18.2.

[0034] As shown in [Fig.5], a measuring plug 21.1-21.4 of axis X comprises a tubular wall 23 and an end wall 24 comprising the passage hole 22.1-22.4 of a measuring tip constituted by a hole passing through a thickness of the end wall 24. The tubular wall 23 has a section complementary to that of the access opening 12.1-12.4 to a voltage measurement interface 15.1-15.4. The tubular wall 23 in this case has a round section but may alternatively have a rectangular or square section depending on the shape of the access openings 12.1-12.4.

[0035] As illustrated in [Fig.4], the operator inserts the measuring tips 18.1, 18.2 of the absence of voltage tester 17 inside two holes 22.1, 22.2 of two measuring plugs 21.1, 21.2 associated with the measuring interfaces 15.1, 15.2 of the fuel cell to ensure the absence of voltage at the terminals of the fuel cell.

[0036] The operator then inserts the measuring tips 18.1-18.2 of the absence of voltage tester 17 inside two holes 22.3, 22.4 of two measuring plugs 21.3, 21.4 associated with the measuring interfaces 15.3, 15.4 of the electric battery to ensure the absence of voltage at the terminals of the battery.

[0037] Once the voltage measurements have made it possible to verify the absence of voltage at the terminals of the electrical components connected to the converter 10 (the fuel cell and the electric battery), the operator removes the measuring plugs 21.1-21.4 and replaces the sealing plugs 16.1-16.4 inside the access openings 12.1-12.4 to the measuring interfaces of the DCDC converter 10. The operator can then work on the vehicle in complete safety without risk of electrocution.

[0038] Alternatively, the voltage absence tester 17 may be replaced by a voltmeter or any other test device suitable for the application.

Claims

Claims

1. Method for securing a DC-DC converter (10) for voltage measurement by means of a test device (17) comprising two measuring tips (18.1, 18.2), characterized in that said method comprises: - a step of removing sealing plugs (16.1-16.4) closing access openings (12.1-12.4) to voltage measurement interfaces (15.1-15.4), said access openings (12.1-12.4) being made in a housing (13) of the DC-DC converter (10), - a step of placing measuring plugs (21.1-21.4) inside the access openings (12.1-12.4) to the voltage measurement interfaces (15.1-15.4), the measuring plugs (21.1-21.4) comprising a through hole (22.1-22.4) of a measuring tip (18.1, 18.2) of the test device (17), and - a step of inserting each measuring tip (18.1, 18.2) of the test device (17) inside a through hole (22.1-22.4) a measuring tip made in a corresponding measuring plug (21.1-21.4) to ensure the absence of voltage at the terminals of an electrical component electrically connected to the DC-DC converter (10).

2. Method according to claim 1, characterized in that it comprises a step of verifying the absence of voltage at terminals of a fuel cell.

3. Method according to claim 1 or 2, characterized in that it comprises a step of verifying the absence of voltage at terminals of an electric battery.

4. Method according to any one of claims 1 to 3, characterized in that it further comprises a step of removing the measuring plugs (21.1-21.4) and a step of replacing the sealing plugs (16.1-16.4) inside the access openings (12.1-12.4) to the voltage measuring interfaces (15.1-15.4).

5. Assembly for a motor vehicle characterized in that it comprises: - a DC-DC converter (10) comprising connection terminals (11.1-11.4) to at least two electrical components, said DC-DC converter (10) comprising at least two voltage measurement interfaces (15.1-15.4) associated with an electrical component, and a housing (13) in which at least two access openings (12.1-12.4) are made to the voltage measurement interfaces (15.1-15.4), and - at least two measuring plugs (21.1-21.4) intended to close the access openings (12.1-12.4) to the voltage measuring interfaces (15.1-15.4), each measuring plug (21.1-21.4) having a passage hole (22.1-22.4) for a measuring tip of a test device (17).

6. Assembly according to claim 5, characterized in that each passage hole (22.1-22.4) of a measuring tip has a maximum dimension substantially equal to a diameter of a measuring tip of the test device (17).

7. Assembly according to claim 5 or 6, characterized in that each measuring plug (21.1-21.4) comprises a tubular wall (23) and an end wall (24) comprising the passage hole (22.1-22.4) of a measuring tip.

8. Assembly according to claim 7, characterized in that the tubular wall (23) has a section complementary to that of an access opening (12.1-12.4) to a voltage measurement interface (15.1-15.4).

9. Assembly according to any one of claims 5 to 8, characterized in that each passage hole (22.1-22.4) of a measuring tip has a diameter less than 10 mm.

10. Motor vehicle comprising an assembly defined according to any one of claims 5 to 9.

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