Transaxle case protector

Abstract

This product provides a transaxle case protector that allows for the detection of deformation caused by road surface interference without the need for visual inspection. [Solution] The protector 50 is provided with a projection 54 that contacts the transaxle case 42 as the protector 50 deforms due to road surface interference. As a result, when the protector 50 deforms due to road surface interference, the projection 54 on the protector 50 contacts the transaxle case 42, and the vibration of the transaxle case 42 is transmitted to the protector 50, causing the protector 50 to emit a sound. Therefore, deformation of the protector 50 due to road surface interference can be recognized without the need for visual inspection.

Description

Technical Field

[0001] The present invention relates to a protector for a transaxle case that protects the transaxle case from road surface interference.

Background Art

[0002] There is known a protector for a transaxle case that is disposed on the lower side of the vehicle of the transaxle case and protects the transaxle case from road surface interference. For example, the protection plate for a vehicle transaxle case described in Patent Document 1 is such a protector. In this Patent Document 1, a filler having plasticity is filled between a case flange and a cover flange as the transaxle case and a protection plate as the protector, and the deformation of the protection plate due to road surface interference can be confirmed by the outflow state of the filler.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the protector (protection plate) for the transaxle case described in Patent Document 1, in order to recognize the deformation of the protector (protection plate) due to road surface interference, it was necessary to visually confirm the outflow state of the filled filler.

[0005] The present invention has been made against the background of the above circumstances, and an object thereof is to provide a protector for a transaxle case that can recognize deformation due to road surface interference without requiring visual confirmation.

Means for Solving the Problems

[0006] The gist of the first invention is (a) a transaxle case protector positioned on the lower side of the transaxle case of the vehicle and protecting the transaxle case from road surface interference, and (b) the protector is provided with a projection that, when the protector deforms due to road surface interference, comes into contact with the transaxle case or a component positioned around the transaxle case. [Effects of the Invention]

[0007] According to the first invention, the protector is provided with a projection that contacts the transaxle case or a component located around the transaxle case as the protector deforms due to road surface interference. As a result, when the protector deforms due to road surface interference, the projection on the protector contacts the transaxle case or a component located around the transaxle case, and vibrations from the transaxle case or the component located around the transaxle case are transmitted to the protector, causing the protector to emit a sound. Therefore, deformation of the protector due to road surface interference can be recognized without the need for visual inspection. [Brief explanation of the drawing]

[0008] [Figure 1] This figure illustrates an example of a vehicle to which the present invention is applied. [Figure 2] This diagram illustrates an example of a general configuration for a transaxle case protector, with (a) showing the protector before deformation and (b) showing the protector after deformation. [Figure 3] This diagram illustrates another embodiment of the transaxle case protector. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the following embodiments, the drawings have been simplified or modified as appropriate, and the dimensional ratios and shapes of each part are not necessarily accurately depicted. [Examples]

[0010] Figure 1 illustrates an example of a vehicle 10 to which the present invention is applied. Figure 1(a) illustrates an example of the schematic configuration of the vehicle 10. In Figure 1(a), the vehicle 10 is an electric vehicle equipped with an electric motor MG that functions as a power source. The vehicle 10 also includes drive wheels 12, a drive shaft 28, and a transaxle 40.

[0011] The transaxle 40 comprises an electric motor MG, a power transmission device 16, and a transaxle case 42 that houses the electric motor MG and the power transmission device 16.

[0012] An electric motor MG is a known rotating electric machine that has the function of an engine that generates mechanical power from electric power and the function of a generator that generates electric power from mechanical power, and is a so-called motor generator.

[0013] The power transmission device 16 is a device that transmits power output from the electric motor MG to the drive wheels 12 via the drive shaft 28, and is equipped with a reduction gear group and a differential gear system (not shown) inside. The connecting shaft 14, which is the input shaft of the power transmission device 16, is connected to the rotor shaft of the electric motor MG, and the power output from the electric motor MG is transmitted to the power transmission device 16. The power transmitted to the power transmission device 16 is converted into driving force for travel by the reduction gear group and differential gear system inside the power transmission device 16, and is transmitted to the drive wheels 12 via the drive shaft 28 connected to the differential gear system.

[0014] The power transmission device 16 has a first axis CL1 and a second axis CL2 that are parallel to each other. The first axis CL1 is the axis of rotation with respect to the electric motor MG and the connecting shaft 14. The second axis CL2 is the axis of rotation with respect to the drive shaft 28.

[0015] Figure 1(b) illustrates an example of the electrical configuration of the vehicle 10, particularly the electrical configuration related to the control of the electric motor MG. In Figure 1(b), the vehicle 10 is equipped with a high-voltage battery 30 and an inverter 32.

[0016] The high-voltage battery 30 is a rechargeable DC power source, such as a nickel-metal hydride secondary battery or a lithium-ion battery. The high-voltage battery 30 is connected to the inverter 32. The stored power from the high-voltage battery 30 is supplied to the electric motor MG via the inverter 32. In addition, power from the regenerative control of the electric motor MG is supplied to the high-voltage battery 30 via the inverter 32.

[0017] The inverter 32 is operated by a command from an electric motor control device (not shown). The inverter 32 is a power control device that controls the power exchanged between the high-voltage battery 30 and the electric motor MG, and is an electric motor control inverter assembly that controls the electric motor MG. The inverter 32 converts the DC current from the high-voltage battery 30 into AC current to drive the electric motor MG. The inverter 32 also converts the AC current generated by the electric motor MG through regenerative braking into DC current.

[0018] Figure 2 is a diagram illustrating an example of the schematic configuration of the protector 50 of the transaxle case 42, which will be described later. The vertical direction of the paper represents the vertical direction of the vehicle 10, and the horizontal direction of the paper represents the width direction of the vehicle 10. It is a side view of the transaxle 40 as seen from the rear in the direction of travel of the vehicle 10. Figure 2(a) shows the protector 50 before deformation, and Figure 2(b) shows it after deformation.

[0019] The transaxle case 42 is a non-rotating case that is a non-rotating member attached to the vehicle body, and includes a housing 42a as the first case, a case body 42b as the second case, and a cover 42c as the third case. The housing 42a and the case body 42b are integrally connected by a fastener such as a bolt so that the opened portion on the left side of the paper surface of the housing 42a and the opened portion on the right side of the paper surface of the case body 42b are combined. The case body 42b and the cover 42c are integrally connected by a fastener so as to close the opened portion on the left side of the paper surface of the case body 42b with the cover 42c.

[0020] The case body 42b is a case including a partition wall 40b1 that partitions an electric motor chamber Rm that houses the electric motor MG and a gear chamber Rg that houses the power transmission device 16. In the transaxle case 42, the gear chamber Rg is formed by the joining of the housing 42a and the case body 42b, and the electric motor chamber Rm is formed by the joining of the case body 42b and the cover 42c.

[0021] In the electric motor chamber Rm, the main body of the electric motor MG is fixedly non-rotatable, and a rotor shaft MGr integrated with the rotor, which is a rotating body of the electric motor MG, is rotatably supported by a bearing 46. Also, preferably, an inverter 32 may be simultaneously housed in the electric motor chamber Rm.

[0022] The power transmission device 16 is housed in the gear chamber Rg. A connecting shaft 14, which is an input shaft of the power transmission device 16, is connected to the rotor shaft of the electric motor MG, and the connecting shaft 14 is rotatably supported by a bearing 44. In addition, the rotating shafts of a reduction gear group and a differential gear device (not shown) inside the power transmission device 16 are also rotatably supported by bearings (not shown). A drive shaft 28 inserted from the openings 42a1 and 42c1 of the transaxle case 42 (housing 42a, cover 42c) is connected to the differential gear device. Also, the drive shaft 28 is rotatably supported by a bearing 48.

[0023] In FIG. 2(a), a protector 50 provided to protect the transaxle case 42 from road surface interference includes a protector body 52 and a protrusion 54.

[0024] The protector body 52 is arranged to cover the vehicle lower side of the transaxle case 42, and is fastened to the transaxle case 42 by a fastener such as a bolt via a spacer 56 so as to secure a gap S therebetween.

[0025] The protrusion 54 is a member that rises obliquely upward from the horizontal central portion where the protector body 52 covers the lower side of the transaxle case 42 and then extends horizontally, and the horizontally extending portion is arranged to face the transaxle case 42. The protrusion 54 is fixed to the protector body 52 by, for example, adhesion, welding, or fastening with bolts or the like. The height T of the protrusion 54 is smaller than the gap S (T < S), and when the protector body 52 is not deformed, the protrusion 54 and the transaxle case 42 do not contact each other, and a suitable value for contact when the protector body 52 is deformed is preset. Further, the protrusion 54 is formed with a rigidity and shape that are easily deformed so that when the protrusion 54 contacts the transaxle case 42, the contact portion of the protrusion 54 does not transmit a load to the transaxle case 42 in the contact state. For example, when the deformation amount of the protector body 52 is large and the gap S is smaller than the height T (S < T), the protrusion 54 is bent in the direction of the protector body 52. Hereinafter, the deformation of the protector body 52 will be described as the deformation of the protector 50.

[0026] Figure 2(b) shows the case where the protector 50 deforms upward due to road surface interference from below by the vehicle 10. As the protector 50 deforms upward, the gap S decreases to a height T or less (S ≤ T), and the projection 54 comes into contact with the transaxle case 42, as shown in the area enclosed by the dashed line in Figure 2(b). As a result of the contact, vibrations from the electric motor MG and power transmission device 16 in the transaxle case 42, as well as sounds generated at the contact point of the projection 54 due to the vibrations, are transmitted to the protector 50, causing the protector 50 to emit sound.

[0027] The protector body 52 is designed to deform as shown in Figure 2(b) when subjected to input (load or impact) from road surface interference, thereby preventing the input from being directly transmitted to the transaxle case 42, and to prevent the protector body 52 from coming into contact with the transaxle case 42. This is achieved through rigidity, shape, and dimensions (including the gap S). While metal materials are preferably used for the protector body 52 and the protrusions 54, other materials may be preferably used, or composite materials may be used, as long as they can meet the required rigidity and shape. Furthermore, the protrusions 54 may be given properties such as spring characteristics or elasticity.

[0028] As described above, according to this embodiment, the protector 50 is provided with a projection 54 that contacts the transaxle case 42 as the protector 50 deforms due to road surface interference. As a result, when the protector 50 deforms due to road surface interference, the projection 54 on the protector 50 contacts the transaxle case 42, and vibrations from the transaxle case 42 are transmitted to the protector 50, causing the protector 50 to emit a sound. Therefore, deformation of the protector 50 due to road surface interference can be recognized without the need for visual inspection. [Examples]

[0029] Next, other embodiments of the present invention will be described. Parts common to Embodiment 1 described above will be denoted by the same reference numerals and their descriptions will be omitted.

[0030] Figure 3 shows an example in which protector 50 in the aforementioned Example 1 (Figure 2) is replaced with protector 60. Similar to Figure 2, Figure 3(a) shows protector 60 before deformation, and Figure 3(b) shows it after deformation.

[0031] In Figure 3(a), the protector 60 is provided with two protrusions 62 and 64 instead of the protrusion 54 of the aforementioned Embodiment 1 (Figure 2). The protrusions 62 and 64 are substantially L-shaped members extending from the horizontal central part of the protector body 52 that covers the lower side of the transaxle case 42, and are positioned so that the tip corresponding to the upper end of the L-shape faces the drive shaft 28. In Figure 3(b), as the protector body 52 (hereinafter referred to as the protector 60 in relation to deformation) deforms upward due to road surface interference from below by the vehicle 10, the gap S decreases, and consequently the protrusions 62 and 64 move upward, and as shown in the area enclosed by the dashed line in Figure 3(b), the respective tips of the protrusions 62 and 64 come into contact with the drive shaft 28. Upon contact, vibrations from the drive shaft 28 and vibrations and sounds generated due to rotational friction at the contact points of the protrusions 62 and 64 are transmitted to the protector 60, causing the protector 60 to emit sound.

[0032] The protrusions 62 and 64 are formed with rigidity (including spring characteristics and elasticity, etc.) and shape such that, similar to the protrusion 54 in Embodiment 1, their respective tips do not transmit load to the drive shaft 28 when in contact with it. Preferably, the tips of the protrusions 62 and 64 that contact the drive shaft 28 may be made of a material that produces a loud sound due to rotational friction with the drive shaft 28.

[0033] As described above, in this embodiment, the protector 60 is provided with protrusions 62 and 64 that come into contact with the drive shaft 28, a component located around the transaxle case 42, as the protector 60 deforms due to road surface interference. As a result, when the protector 60 deforms due to road surface interference, the protrusions 62 and 64 on the protector 60 come into contact with the drive shaft 28, the vibration of the drive shaft 28 is transmitted to the protector 60, and the protector 60 emits sound. Therefore, in this embodiment as well, the same effects as in the previously described embodiment 1 can be obtained.

[0034] Although embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is also applicable to other embodiments.

[0035] For example, in the above-described embodiment 1, the projection 54 was raised diagonally upward from the protector body 52 and then extended horizontally, but it is not limited to this shape. The projection 54 only needs to have the rigidity and shape to bend in the direction of the protector body 52 so that when it comes into contact with the transaxle case 42, the contact point does not transmit load when in contact, and may, for example, be raised vertically in an inverted J shape.

[0036] Furthermore, in the above-described embodiments 1 and 2, the protectors 50 and 60 were fastened to the transaxle case 42 via spacers 56. However, without using spacers 56, shapes or other features to secure the gap S may be formed in the transaxle case 42 or the protectors 50 and 60. Also, the protectors 50 and 60 may be fixed to, for example, the body of the vehicle 10, without being fastened to the transaxle case 42.

[0037] Furthermore, while the above-described embodiments 1 and 2 involved protectors 50 and 60 for the transaxle case 42 of an electric vehicle 10, the present invention is not limited to this embodiment. For example, the present invention can also be applied to protectors for the transaxle case of a vehicle equipped with an engine as a power source, or a hybrid vehicle equipped with both an engine and an electric motor.

[0038] It should be noted that the above-described embodiment is merely one example, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of Symbols]

[0039] 10: Vehicle 28: Drive shaft (parts arranged around it) 42: Transaxle case 50, 60: Protector 54, 62, 64: Protrusions

Claims

[Claim 1] A transaxle case protector, positioned on the lower side of the transaxle case of the vehicle, which protects the transaxle case from road surface interference, The protector is provided with protrusions that, when the protector deforms due to road surface interference, come into contact with the transaxle case or components located around the transaxle case. A transaxle case protector characterized by the following:

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