Method for connecting metal housing and plastic cover, and metal housing comprising plastic cover

Abstract

The invention relates to a method for connecting a metal housing (1) and a plastic cover (2), wherein: the metal housing (1) is provided; overmoulding a metal sleeve (3) with a plastic material at least partially to form the plastic cap (2), the metal sleeve having a groove (4) extending at least partially in the circumferential direction; the plastic cover (2) is axially pressed together with the metal sleeve (3) into the metal housing (1) such that the metal sleeve (3) is arranged at least on the circumference of the metal housing (1). The invention also relates to a metal housing (1) comprising a plastic cover (2), in which a metal sleeve (3) is located at least partially between the metal housing (1) and the plastic cover (2), the metal sleeve (3) having a recess (4) which extends at least partially on the periphery and is at least partially overmolded with plastic, the metal sleeve (3) is arranged at least on the circumference of the metal housing (1) and has an interference fit in the metal housing (1).

Description

Technical Field

[0001] The invention relates to a method for connecting a metal housing and a plastic cover. In addition, the invention relates to a metal housing with a plastic cover. Background Art

[0002] Usually, the metal shell and the plastic cover are screwed together or connected in a way that the plastic cover is pressed into the metal shell. However, due to the different materials of metal and plastic, the interference fit between the metal shell and the plastic cover is not ideal and may cause a reduction in holding force.

[0003] DE 10 2020 131 326 A1 discloses an electric motor for driving an actuator of a motor vehicle. The electric motor has a housing with a housing base body and a plug-in module, which forms a housing wall of the housing and encloses an interior together with the housing base body. The plug-in module has a connector arranged outside the interior. In addition, a screw with a screw head is provided, by means of which the plug-in module is attached to the housing base body, wherein the screw is arranged completely inside the interior. Summary of the invention

[0004] The object of the invention is to provide an alternative method for connecting a metal housing and a plastic cover and an alternative metal housing with a plastic cover. In particular, the connection between the metal housing and the plastic cover should exhibit a high holding force and be particularly durable. These objects are achieved by the subject matter of patent claims 1 and 6. Preferred embodiments can be found in the dependent claims.

[0005] With regard to the method for connecting a metal shell and a plastic cover according to the invention, a metal shell is provided, i.e., a metal shell mainly made of a metal material, wherein a metal sleeve is at least partially overmolded with a plastic material to form a plastic cover, the metal sleeve having a groove extending at least partially in a circumferential direction, wherein the plastic cover is axially pressed into the metal shell together with the metal sleeve so that the metal sleeve is at least partially arranged on the circumference of the metal shell.

[0006] The connection between the metal sleeve and the plastic material is a form fit, because the metal sleeve is at least partially or completely overmolded with the plastic material. In contrast, the connection between the metal sleeve and the metal housing is a force fit, because the plastic cover is axially pressed into the metal housing, so that an interference fit is formed between the metal sleeve and the metal housing.

[0007] The metal sleeve, which is arranged spatially between the metal housing and the plastic cover, forms a particularly durable connection between the metal housing and the plastic cover and exhibits a high holding force. In addition, the metal sleeve reliably prevents damage to the plastic cover when the metal sleeve is pressed into the metal housing. Preferably, the metal housing and the metal sleeve are made of the same material. For example, the metal housing and the metal sleeve are made of an aluminum alloy and therefore have the same material properties, in particular the same coefficient of thermal expansion. Due to the same coefficient of thermal expansion, the metal housing with the plastic cover can be used for applications over a wide temperature range without affecting the connection between the metal housing and the plastic cover.

[0008] Pressing the plastic cover into the metal housing means that the plastic cover and the metal housing are axially displaced relative to one another, i.e. the two components are either moved towards one another or at least one of the two components is moved in the direction of the other component, wherein a force-fit connection, i.e. an interference fit, is achieved at the circumferential surface of the metal housing and the metal sleeve. It therefore makes no difference whether the plastic cover is axially pressed into the metal housing or the metal housing is axially pressed onto the plastic cover. In particular, the metal housing and the plastic cover are designed to be cylindrical.

[0009] A groove is to be understood as a toothing, i.e. a structured area with ridges and recesses arranged alternately in the circumferential direction. The geometry of the groove or toothing can be rounded or angular and is designed to be overmolded with plastic material in order to better transmit any torque by form fit. The groove also strengthens the form-fit connection between the metal sleeve and the plastic material. The groove on the metal sleeve is preferably completely overmolded with plastic material. In other words, the ridges and recesses are completely covered with plastic material.

[0010] Preferably, the groove is formed on an axially defined section of the inner circumferential surface of the metal sleeve. For example, the groove on the inner circumferential surface of the metal ring is designed to be completely circumferential. Alternatively, a plurality of groove areas are arranged to be spaced apart from each other in the circumferential direction.

[0011] According to a preferred embodiment, an at least partially circumferential shoulder is formed on the metal sleeve, wherein the plastic cover is pressed axially into the metal shell until the at least partially circumferential shoulder abuts against the end face of the metal shell. In other words, the cylindrical metal sleeve has a shoulder, wherein the shoulder is preferably formed on the outer peripheral surface of the metal sleeve and therefore extends radially outward. Therefore, the metal sleeve rests against the metal shell both on the circumference and on the end face. The metal sleeve is preferably made of an aluminum profile, wherein the at least partially circumferential shoulder on the aluminum profile is preferably made by means of a forming process. For example, the shoulder on the metal sleeve is designed to be completely circumferential. Alternatively, a plurality of shoulders are arranged to be spaced apart from each other in the circumferential direction.

[0012] According to a preferred embodiment, a sealing ring is radially arranged between the metal housing and the plastic cover. The sealing ring is preferably arranged in a groove provided for it on the plastic cover and is made of a rubber material. In particular, the sealing ring is in fluid-tight and circumferential contact between the inner circumferential surface of the metal housing and the outer circumferential surface of the plastic cover.

[0013] The metal housing with plastic cover according to the invention has a metal sleeve, which is at least partially arranged between the metal housing and the plastic cover, wherein the metal sleeve has an at least partially circumferential groove, which is at least partially overmolded with plastic material, wherein the metal sleeve is arranged at least on the circumference of the metal housing and exhibits an interference fit in the metal housing. The interference fit between the metal housing and the metal sleeve of the plastic cover ensures that the metal housing and the plastic cover are indirectly connected in a force-fitting manner via the metal sleeve.

[0014] The electric machine according to the invention has a metal housing with a plastic cover according to the invention. In particular, the metal housing with a plastic cover according to the invention is produced using the method according to the invention. For example, the electric machine is intended for use in a motor vehicle, in particular for driving an actuator. The plastic cover of the metal housing is designed as a plug-in module. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other measures for improving the present invention are shown in more detail below together with the description of preferred embodiments of the present invention based on the accompanying drawings. In the accompanying drawings:

[0016] Figure 1 shows a schematic perspective view of a metal sleeve,

[0017] Figure 2 Shown with Figure 1 A schematic perspective cross-sectional view of a plastic cover of a metal sleeve, and

[0018] Figure 3 Shown with Figure 2 Schematic cross-sectional view of a portion of a metal housing with a plastic cover. DETAILED DESCRIPTION

[0019] according to Figure 1 The cylindrical metal sleeve 3 is preferably made of aluminum alloy and has a groove 4 extending in the circumferential direction on the inner circumferential surface and a shoulder 5 extending in the circumferential direction on the outer circumferential surface.

[0020] Figure 2 A plastic cover 2 is shown, which is formed by Figure 1The metal sleeve 3 shown is formed by overmolding. In other words, the metal sleeve 3 is placed in an injection mold and overmolded with a plastic material to form the plastic cover 2. The inner peripheral surface of the metal sleeve 3 and the groove 4 formed on the inner peripheral surface of the metal sleeve 3 are completely overmolded with the plastic material, and thus Figure 2 No plastic material is provided on the outer peripheral surface of the metal sleeve 3.

[0021] Figure 3 A plastic cover 2 is shown which is arranged in a metal housing 1, wherein a metal sleeve 3 is arranged on the inner circumferential surface of the metal housing 1 via an outer circumferential surface. The plastic cover 2, i.e. the metal sleeve 3 overmolded with plastic material, exhibits an interference fit with the metal housing 1. The shoulder 5 on the outer circumferential surface of the metal sleeve 3 enables a local increase in the outer diameter of the metal sleeve 3. The plastic cover 2 is pressed axially into the metal housing 1 until the shoulder 5 of the metal sleeve 3 abuts against the end face of the metal housing 1. The shoulder 5 on the metal sleeve 3 thus serves as an axial stop surface for positioning the plastic cover 2 in the metal housing 1. The metal sleeve 3 rests against the metal housing 1 both circumferentially and on the end face.

[0022] Furthermore, a sealing ring 6 is radially arranged between the metal housing 1 and the plastic cover 2 , which is in fluid-tight and circumferential contact between the inner peripheral surface of the metal housing 1 and the outer peripheral surface of the plastic cover 2 .

[0023] The metal shell 1 and the metal sleeve 3 are made of the same material and therefore have the same thermal expansion coefficient, thereby improving the durability and retention of the interference fit. In this example, the metal shell 1 and the metal sleeve 3 are made of aluminum alloy.

[0024] Reference numerals list

[0025] 1 Metal housing

[0026] 2 Plastic cover

[0027] 3 Metal sleeve

[0028] 4 Grooves

[0029] 5 Shoulder on the metal sleeve

[0030] 6 Sealing ring

Claims

1. A method for connecting a metal housing (1) and a plastic cover (2), wherein: A metal shell (1) is provided, wherein a metal sleeve (3) is at least partially overmolded with a plastic material to form the plastic cover (2), the metal sleeve having a groove (4) extending at least partially in a circumferential direction, wherein the plastic cover (2) is axially pressed into the metal shell (1) together with the metal sleeve (3) so that the metal sleeve (3) is arranged at least on the circumference of the metal shell (1).

2. The method according to claim 1, It is characterized in that The groove (4) is formed on an axially defined section of the inner peripheral surface of the metal sleeve (3).

3. The method according to any one of the preceding claims, It is characterized in that The groove (4) on the metal sleeve (3) is completely over-moulded with plastic material.

4. The method according to any one of the preceding claims, It is characterized in that An at least partially circumferential shoulder (5) is formed on the metal sleeve (3), wherein the plastic cover (2) is axially pressed into the metal shell (1) until the at least partially circumferential shoulder (5) abuts against the end face of the metal shell (1).

5. The method according to any one of the preceding claims, It is characterized in that A sealing ring (6) is radially arranged between the metal housing (1) and the plastic cover (2).

6. A metal housing (1) with a plastic cover (2), wherein: A metal sleeve (3) is at least partially arranged between the metal shell (1) and the plastic cover (2), wherein the metal sleeve (3) has an at least partially circumferential groove (4), and the at least partially circumferential groove is at least partially overmolded with plastic material, wherein the metal sleeve (3) is at least arranged on the circumference of the metal shell (1) and exhibits an interference fit in the metal shell (1).

7. The metal housing (1) according to claim 6, It is characterized in that The metal shell (1) and the metal sleeve (3) are made of the same material.

8. The metal housing (1) according to claim 6 or 7, It is characterized in that The metal shell (1) and the metal sleeve (3) are made of aluminum alloy.

9. The metal housing (1) according to any one of claims 6 to 8, It is characterized in that The metal sleeve (3) rests against the metal housing (1) both on the circumference and on the end faces.

10. An electric machine having a metal housing (1) according to any one of claims 6 to 9.

Images