Electric-parking-brake-actuator electrical connector

Abstract

An electric-parking-brake-actuator electrical connector (10) which electrically connects a motor (42) of an electric-parking-brake actuator (40) to an electrical power supply (50). The electric-parking-brake-actuator electrical connector includes a first connection portion (12), a second connection portion (14) and an electrical conductor body (16) 5 connecting the first connection portion (12) with the second connection portion (14). The electrical conductor body (16) defines a path which extends in three spatial dimensions and is resiliently flexible.

Description

[0001] Electric-Parking-Brake-Actuator Electrical Connector

[0002] The present invention relates to an electrical connector, in particular an electric-parking- brake-actuator electrical connector, for electrically connecting a motor of an electric- parking-brake actuator to an electrical power supply. The invention further relates to an electric-parking-brake actuator and to a method of connecting an electrical connector to a motor and to an electrical power supply.

[0003] An actuator of an electric parking brake, also known as an electronic parking brake, generally comprises of a motor and a gear box.

[0004] When the electric parking brake is activated, for example by pressing a button, the motor is supplied with electrical power to rotate. The rotational motion is transmitted to an idle gear or belt which drives a gear box, increasing the torque. The rotational motion of the output of the gear box is used to ultimately result in the brakes being actuated and stop the wheels from rotating.

[0005] If the motor is rigidly coupled to a housing of the actuator, then actuation of the motor may generate and transmit vibrations from the motor to the housing, causing noise, vibration, and / or harshness (NVH). NVH is undesirable, particularly in high-end vehicles.

[0006] Furthermore, the actuator is typically mounted to a non-suspended part of the vehicle, such as the wheel hub. Therefore, the actuator can undergo significant reciprocating forces when the vehicle is driven over an uneven road surface, referred to as forced vibration. The forced vibration can make the motor move relative to the housing of the actuator, resulting in damage to components connected therebetween. Such components may be damaged by fatigue. As such, the actuator is required to undergo strenuous forced vibration testing, to check its durability.

[0007] It is an object of the present invention to reduce or substantially obviate the above problem. The present invention seeks to provide a solution to this problem.

[0008] The present invention seeks to provide a solution to these problems.

[0009] According to a first aspect of the invention, there is provided an electric-parking-brake- actuator electrical connector for electrically connecting a motor of an electric-parking- brake actuator to an electrical power supply, the electric-parking-brake-actuator electrical connector comprising: a first connection portion for connecting with the motor; a second connection portion for connecting with the electrical power supply; an electrical conductor body connecting the first connection portion with the second connection portion, the electrical conductor body defining a path between the first connection portion and the second connection portion; the path extending in three spatial dimensions and the electrical conductor body being resiliently flexible.

[0010] The electrical power supply, which may here include wiring or other electrical conduits from the electrical power source, may typically be fixed relative to a housing of the electric-parking-brake actuator. The motor may be mounted in the housing with rubber between the motor and the housing so that the motor is effectively mechanically suspended relative to the housing, preventing or limiting vibrations travelling from the motor to the housing. However, if a rigid electrical connection is made between the electrical power supply and the motor, vibrations may still be transferred to the housing via this rigid connection. As such, the electric-parking-brake actuator may generate significant NVH.

[0011] If, instead, an electrical connection is made between the motor and electrical power supply by slack or loose conductors, such as cables or wiring, then this may require cable shoes or similar, which are not compatible with automation and may cause issues when exposed to forced vibration, such as in forced vibration tests. The cables or wiring may move undesirably and / or fail in fatigue.

[0012] Therefore, the invention provides a resiliently flexible electrical conductor body with a three-dimensional shape. The resilience means that cable shoes are not required, allowing automation, and the electrical connection is not provided by slack conductors, which improves NVH due to no excessive movement of cables. The three-dimensional shape has the result that the body can flex in different directions and effectively does not rigidly mechanically couple the motor with the housing. Vibration displacement is reduced, releasing stress on the part and minimising the risk of failure, particularly by fatigue.

[0013] The path extends smoothly over a long extent, avoiding edges and / or large section changes, which minimises local deformation and stress, providing greater fatigue resistance.

[0014] The electric-parking-brake-actuator electrical connector may be considered to be a lead frame. Preferably, the electrical conductor body may have an elongate cross-section. The electrical conductor body is strip or plate shaped. A strip or plate shape may provide greater resilience than a wire shape, for example.

[0015] In a preferable embodiment, the path may be curvate. The curvature of the body may allow for greater flexibility.

[0016] Advantageously, the path may comprise an arch or wave. The arch or wave shape similarly allows for greater flexibility.

[0017] Optionally, the arch or wave includes a kink. Here, the arch may have one portion aligned in the X-Z plane, then a section which extends out of the X-Z plane in the Y-Z plane, before the arch completes in the X-Z plane. The kink is defined by the deviation from the X-Z plane. Providing such an arrangement reduces vibration displacement.

[0018] Preferably, the first and second connection portions may be displaced from each other in first and second axes, the path extending in the first and second axes at locations which are displaced from the first and second connection portions in a third axis. For example, the first and second connection portions may be displaced from each other in X and Y directions. The path can then extend in the X and Y directions at locations which are above or below the first and second connection portions in the Z axis.

[0019] Beneficially, the first connection portion may be at a first end of the electrical conductor body, and the second connection portion may be at a second end of the electrical conductor body.

[0020] Preferably, the first connection portion and the second connection portion may be configured to be press-fitted or crimped to a terminal of the motor and an electrical pin of the power supply respectively.

[0021] A press-fit or crimping connection may be compatible with automation and so allow for more convenient manufacture.

[0022] Advantageously, the first connection portion may comprise a hole for receiving a terminal of the motor, and the second connection portion may comprise a hole for receiving an electrical pin of the electrical power supply.

[0023] Optionally, the first connection portion and the second connection portion may each comprise at least one projection for contacting the terminal of the motor and the electrical pin respectively when received through the respective hole. The hole and teeth may allow for the connection to be made via crimping or a press-fit.

[0024] Preferably, the electrical conductor body may comprise copper, particularly a solid solution strengthened copper alloy.

[0025] Copper has a good fatigue resistance, and so is suitable for use in the electrical conductor body since the actuator can undergo large forced vibration.

[0026] Advantageously, the electrical conductor body may comprise a copper alloy of between 5wt% and 7wt% tin, particularly CuSn6.

[0027] Such materials may provide a suitable balance between resilience, flexibility, and electrical conductivity.

[0028] Beneficially, the electrical conductor body may have a thickness of between 0.25 mm and 1 mm, and particularly is 0.5 mm or substantially 0.5 mm. Such a thickness may provide a good balance between resilience and flexibility.

[0029] In a preferable embodiment, the electric-parking-brake-actuator electrical connector is unitarily formed as a one piece.

[0030] According to a second aspect of the present invention, there is provided an electric- parking-brake actuator comprising: a motor; and at least one electric-parking-brake- actuator electrical connector according to the first aspect of the invention, the first connection portion connected to the motor.

[0031] According to a third aspect of the present invention, there is provided a method of connecting an electric-parking-brake-actuator electrical connector according to a first aspect of the invention, to a motor and an electrical power supply of an electric-parking- brake actuator, the method comprising press-fitting or crimping the first connection portion to a terminal of the motor and the second connection portion to an electrical pin of the power supply.

[0032] The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:

[0033] Figure 1 shows a first embodiment of an electric-parking-brake-actuator electrical connector in accordance with a first aspect of the invention, and which is configured to be used in a left-hand position relative to an electric-parking-brake actuator; Figure 2 shows a second embodiment of an electric-parking-brake-actuator electrical connector in accordance with a first aspect of the invention, and which is configured to be used in a right-hand position relative to the electric-parking-brake actuator;

[0034] Figure 3 shows an elevated view of the electric-parking-brake-actuator electrical connectors of Figures 1 and 2 in use in an electric-parking-brake actuator in accordance with a second aspect of the invention; and

[0035] Figure 4 shows a side view of the electric-parking-brake actuator of Figure 3.

[0036] Referring firstly to Figure 1 , there is shown a first embodiment of an electric-parking- brake-actuator electrical connector 10 having a first connection portion 12, a second connection portion 14 and an electrical conductor body 16 connecting the first connection portion 12 with the second connection portion 14. The electrical connector 10 may be considered to be a lead frame.

[0037] The first connection portion 12 is for connecting with a motor of an electric-parking-brake actuator and the second connection portion 14 is for connecting with a power supply. The first connection portion 12 is at a first end of the electrical conductor body 16, and the second connection portion 14 is at a second end of the electrical conductor body 16.

[0038] The first embodiment is for being used in a left-hand position relative to an electric- parking-brake actuator.

[0039] The first and second connection portions 12, 14 each comprise a hole 18, which is preferably an aperture. The hole 18 is elongate, and may be generally rectangular. The first and second connection portions 12, 14 are similar or identical to each other, with the main exception that a longitudinal direction of the hole 18 of the first connection portion 12 is transversely aligned relative to the longitudinal direction of the hole 18 of the second connection portion 14. Additionally, a rim 20 of the first connection portion 12 is wider than that of the second connection portion 14. However, it will be appreciated that other configurations may be considered.

[0040] Each of the first and second connection portions 12, 14 includes at least one projection or tooth extending at least part way across the hole 18. Here each connection portion 12, 14 includes three such teeth, with two teeth 22 on one elongate side of the hole 18 and one larger tooth 24 on the opposing elongate side of the hole 18. The two teeth 22 are aligned at either side of the single tooth 24, which can provide an improved gripping action. Whilst the preceding arrangement of teeth is described, it will be appreciated that differing numbers, sizes or positions of teeth may be included.

[0041] The teeth 22, 24 here allow the first connection portion 12 and the second connection portion 14 to be press-fitted or crimped to the motor and electrical power supply respectively. However, it will be appreciated that other means for permitting a press-fit or crimped connection may be considered.

[0042] The electrical conductor body 16 acts as a mechanically self-supporting electrical bridge between the first and second connection portions 12, 14, whilst minimising NVH. As such, the electrical conductor body 16 should be formed from a material of suitable electrical and mechanical properties.

[0043] As such, the electrical conductor body 16 should be formed from an electrically conductive material and should be resiliently flexible. Resiliently flexible will be understood to mean to be able to elastically deform under stress, but return to its previous shape. This contrasts with wiring or cabling, which are loose or slack.

[0044] A suitable such material is copper, and the electrical conductor body 16 preferably comprises copper, in particular a solid solution strengthened copper alloy, such as one comprising between 5wt% and 7wt% tin. CuSn6 is a suitable such alloy. However, it will be appreciated that other alloys of copper or engineering materials which are good conductors of electricity may also be considered.

[0045] To increase resilience, the electrical conductor body 16 is generally strip-shaped or substantially strip-shaped. In other words, the electrical conductor body 16 is elongate, and has an elongate cross-section. The electrical conductor body 16 preferably has a thickness of around 0.5 mm.

[0046] The first and second connection portions 12, 14 are also electrical conductors, and may preferably be formed from the same material as the electrical conductor body 16, for example being unitarily formed as a one piece with the electrical conductor body 16.

[0047] The electrical conductor body 16 defines a path between the first connection portion 12 and the second connection portion 14. This path extends in three dimensions, and in particular three orthogonal dimensions. In other words, the path is three-dimensional. The path is also elongate between the first connection portion 12 and the second connection portion 14.

[0048] The first and second connection portions 12, 14 are preferably coplanar, although it will be appreciated that this may not necessarily be the case. A plane of an opening of the hole 18 of the first connection portion 12 and the second connection portion 14 is here defined as the XY plane. An axial direction extending out of this plane may be defined as the Z direction. A corresponding XYZ coordinate system is shown for reference in Figure 1. The first and second connection portions 12, 14 are displaced from each other in both the X and Y directions.

[0049] The path of the electrical conductor body 16 initially extends from the first connection portion 12 in the X direction and in the Z direction. The path is preferably at least in part curvate in this regard. The path then reaches a peak 26 in the Z axis. A first path portion 28 may be defined between the first connection portion 12 and the peak 26 in the Z axis.

[0050] The path then curves back down, continuing in the X axis, but descending in the Z axis. This may be defined as a second path portion 30.

[0051] The path then extends in the Y axis alone, so as to align with the second connection portion 14 in the X axis. This extension in the Y axis occurs at a location which is elevated in the Z axis. In other words, the path preferably does not extend in the Y axis when coplanar with the first and second connection portions 12, 14. The extension in the Y axis may be defined as a third path portion 32.

[0052] After the third path portion 32, the path then re-continues in the X and Z axes to meet the second connection portion 14. This final extension in the X and Z axes may be defined as the fourth path portion 34. The fourth path portion 34 may be curvate.

[0053] The path may be arched, rounded or semi-circular at the peak 26. The path extends both upwardly and downwardly in the Z axis. The path may be considered to have a general arch or wave shape. The general arch shape extends in two planes, having a kink therebetween, the first and second path portions 28, 30 extending in a first plane, and the fourth path portion 34 extending in a second plane, both of which are in the X-Z planes. The path preferably does not extend jointly in both the X and Y axes.

[0054] The first and second connection portions 12, 14 have a greater width that that of the electrical conductor body 16. There is therefore a taper between the first and second connection portions 12, 14 and the electrical conductor body 16. The taper 36 at the first connection portion 12 is only at one side of the electrical conductor body 16 and has a curved, and in particular a concave, shape. At the second connection portion 14, the taper is at both sides of the electrical conductor body 16, although this is asymmetrical. At one side 38a the taper is curved and concave, and at the other side 38b the taper is smaller and straight.

[0055] Referring now to Figure 2, there is shown a second embodiment of an electric-parking- brake-actuator electrical connector 110. The second embodiment 110 is similar or identical to the first embodiment 10, having an electrical conductor body 116 and first and second connection portions 112, 114, except that second embodiment is mirrored along the X axis of Figure 1 compared to the first embodiment. The second embodiment is to be used in a right-hand position relative to an electric-parking-brake actuator.

[0056] Referring now to Figures 3 and 4, the first and second embodiments of the electric- parking-brake-actuator electrical connector 10, 110 are installed as part of an electric- parking-brake actuator 40. The first embodiment is attached to one terminal of a motor 42, for example the positive terminal 44 of the motor 42, and the second embodiment is attached to another terminal of the motor 42, for example the negative terminal 46 of the motor 42.

[0057] The positive terminal 44 of the motor 42 extends through the hole 18 of the first connection portion 12 of the first embodiment. The teeth 22, 24 of the first connection portion 12 press against the motor terminal 44. This may be in a press-fit or interference fit arrangement. Alternatively, the teeth 22, 24 may be crimped against the terminal to securely connect the electric-parking-brake-actuator electrical connector 10 thereto. In any case, the interengagement between teeth 22, 24 and terminal ensures a good electrical connection therebetween.

[0058] A pin 48 of the electrical power supply 50 extends through the hole 18 of the second connection portion 14 of the first embodiment. Similarly, the teeth 22, 24 of the second connection portion 14 press against the pin 48 in what may be a press-fit, interference fit, or crimped arrangement.

[0059] The second embodiment 110 connects to the negative terminal 46 of the motor 42 and to another pin 48 of the electrical power supply 50 in a similar or identical way as the first embodiment 10. The electric-parking-brake-actuator electrical connectors 10, 110 may be connected to the motor 42 and power supply 50 via an automated process.

[0060] The electrical power supply 50 can thereby provide electrical power to the motor 42, which can drive the input gear of the gear box. However, the configuration of the electric- parking-brake-actuator electrical connector 10 has the result that the motor 42 and the electrical power supply, which is fixed to a housing 52, may be considered to be mechanically uncoupled. Therefore, the motor 42 and the housing 52 are uncoupled, and vibrations do not pass therebetween, which provides advantages for NVH and reduces the risk of damage by fatigue when undergoing forced vibration.

[0061] It is therefore possible to provide an electrical connector for interconnecting the motor of an electric-parking-brake actuator with an electrical power supply. The electrical connector has a three-dimensional body and is resiliently flexible. The flexibility and three-dimensional shape allow for the motor and power supply to be effectively mechanically uncoupled. The resilience avoids the use of slack electrical conductors with cable shoes, providing greater compatibility for automatic manufacture, reducing NVH issues, and reducing the risk of damage by fatigue when undergoing forced vibration.

[0062] The words ‘comprises / comprising’ and the words ‘having / including’ when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0063] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

[0064] The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.

Claims

Claims1. An electric-parking-brake-actuator electrical connector (10; 110) for electrically connecting a motor (42) of an electric-parking-brake actuator to an electrical power supply (50), the electric-parking-brake-actuator electrical connector comprising: a first connection portion (12; 112) for connecting with the motor (42); a second connection portion (14; 114) for connecting with the electrical power supply (50); an electrical conductor body (16; 116) connecting the first connection portion (12) with the second connection portion (14; 114), the electrical conductor body (16; 116) defining a path between the first connection portion (12; 112) and the second connection portion (14; 114); the path extending in three spatial dimensions and the electrical conductor body (16; 116) being resiliently flexible.

2. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in claim 1 , wherein the electrical conductor body (16; 116) has an elongate crosssection.

3. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the path is curvate.

4. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the path comprises an arch or wave.

5. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in claim 4, wherein the arch or wave includes a kink.

6. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the first and second connection portions (12, 14; 112, 114) are displaced from each other in first and second axes, the path extending in the first and second axes at locations which are displaced from the first and second connection portions (12, 14; 112, 114) in a third axis.

7. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the first connection portion (12; 112) isat a first end of the electrical conductor body (16; 116), and the second connection portion (14; 114) is at a second end of the electrical conductor body (16; 116).

8. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the first connection portion (12; 112) comprises a hole (18) for receiving a terminal (44, 46) of the motor (42), and the second connection portion (14; 114) comprises a hole (18) for receiving an electrical pin (48) of the electrical power supply (50).

9. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the first connection portion (12; 112) and the second connection portion (14; 114) each comprise at least one projection (22, 24) for contacting the terminal (44, 46) of the motor (42) and the electrical pin (48) respectively when received through the respective hole (18).

10. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the first connection portion (12; 112) and the second connection portion (14; 114) are configured to be press-fitted or crimped to a terminal (44, 46) of the motor (42) and an electrical pin (48) of the power supply (50) respectively.

11. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the electrical conductor body (16; 116) comprises a solid solution strengthened copper alloy.

12. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the electrical conductor body (16; 116) comprises a copper alloy of between 5wt% and 7wt% tin.

13. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in claim 12, wherein the copper alloy is CuSn6.

14. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the electrical conductor body (16; 116) has a thickness of between 0.25 mm and 1 mm.

15. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in claim 14, wherein the electrical conductor body (16; 116) has a thickness of 0.5 mm or substantially 0.5 mm.

16. An electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, wherein the electric-parking-brake-actuator electrical connector is unitarily formed as a one piece.

17. An electric-parking-brake actuator (40) comprising: a motor (42); and at least one electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of the preceding claims, the first connection portion (12) connected to the motor (42).

18. A method of connecting an electric-parking-brake-actuator electrical connector (10; 110) as claimed in any one of claims 1 to 17 to a motor (42) and to an electrical power supply (50) of an electric-parking-brake actuator (40), the method comprising press-fitting or crimping the first connection portion (12; 112) to a terminal (44, 46) of the motor (42) and the second connection portion (14; 114) to an electrical pin (48) of the power supply (50).

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