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JP-7855693-B2 - Actuating cylinder

JP7855693B2JP 7855693 B2JP7855693 B2JP 7855693B2JP-7855693-B2

Inventors

  • ブエター、ジョセフ

Assignees

  • ビューマッハ エンジニアリング インターナショナル ベー．フェー．

Dates

Publication Date
20260508
Application Date
20211210

Claims (7)

  1. An operating unit having a cylinder (1) and a piston unit (2), The cylinder (1) comprises a cylinder tube (3), a closure member (4a), and a further closure member (4b). The cylinder tube (3) has a distal cylinder tube end (5a) in the axial direction of the cylinder tube (3) and a further proximal cylinder tube end (5b) opposite to the distal end , the closure member (4a) is provided on the cylinder tube end (5a), and the further closure member (4b) is provided on the further cylinder tube end (5b), The cylinder tube (3) and the closure members (4a, 4b) form the inside of the cylinder (6). The piston unit (2) has at least one working chamber (6.1) inside the cylinder (6), The closure member (4a) has a shaft portion (4a.1), the cylinder tube (3) has a cylinder tube end portion (5a.1), and the shaft portion (4a.1) and the cylinder tube end portion (5a.1) form a connecting section (7a). In the coupling section (7a), the closure member (4a) is inserted axially into the cylinder tube (3) at the cylinder tube end portion (5a.1) by the shaft portion (4a.1), and the coupling section has a proximal region (7a.1) on the proximal side and a distal region (7a.2) on the distal side . The shaft portion (4a.1) has a predetermined conicity, The shaft portion (4a.1) has a dimension that is at least partially larger than the inner diameter of the cylinder tube (3), and the cylinder tube (3) has elastic circumferential expansion therein. The coupling section (7a) is designed to connect the closure member (4a) and the cylinder tube (3) in the manner of axial pressure fitting and shape fitting. The cylinder tube end (5a) is connected to the closure member (4a) by a circumferential ring weld seam (8a), the ring weld seam (8a) is designed as a laser weld seam and forms a pressure medium sealing surface . The conicity is designed to decrease toward the distal side by the diameter of the shaft portion in the proximal region (7a.1), which is larger than the diameter of the shaft portion in the distal region (7a.2), and the shaft portion (4a.1) has a larger dimension than the inner diameter of the cylinder tube (3) in the proximal region (7a.1) of the coupling section (7a). An operating cylinder in which the cylinder tube (3) exhibits elastic circumferential expansion in the proximal region (7a.1) .
  2. The operating cylinder according to claim 1, characterized in that the closure member (4a) has an axial closure member ring surface (4a.2), the cylinder tube (3) has an axial cylinder tube ring surface ( 5a.2 ), and both ring surfaces form a common contact ring surface, and the ring welding seam is provided radially on the contact ring surface.
  3. The operating cylinder according to claim 1 or 2 , characterized in that the conicity of the shaft portion (4a.1) has a conicity angle alpha, and alpha is in the range of 0.1 to 1 degree with respect to the main longitudinal axis 9.
  4. The operating cylinder according to any one of claims 1 to 3 , characterized in that the elastic circumferential expansion of the cylinder tube (3) in the proximal region (7a.1) is 0.02% to 0.5%.
  5. The operating cylinder according to any one of claims 1 to 4 , characterized in that the closure member (4a) has a higher modulus of elasticity than the cylinder tube (3).
  6. The operating cylinder according to any one of claims 1 to 5 , characterized in that the closure member has a chamfered portion (4a.3) at the inlet of the closure member, or the cylinder tube has a chamfered portion (5a.3) at the inlet of the cylinder tube.
  7. The operating cylinder according to claim 2 , characterized in that the cylinder tube ring surface (5a.2) has an inclination angle beta, and beta is in the range of 0.1 to 1 degree.

Description

This invention relates to an operating cylinder, particularly a hydraulic operating cylinder, and a method for manufacturing the same. Such operating cylinders are known from the prior art. Typically, these operating cylinders consist of a cylinder tube and a closure part. According to current technology, such an operating cylinder is manufactured, for example, by screwing together a closure member and a cylinder tube. Such an operating cylinder is also called a screw-type cylinder. Furthermore, it is known from current technology that the base closure member is connected to the cylinder tube by MAG welding, and then the guide closure member is simply screwed in. Typically, the threads on cylinder tubes and closure components are created through a machining process. Both screw-type cylinders and cylinders where one closure member is screw-attached and the other is MAG-welded are supplied with high quality based on current technology, and they have been proven to be top-quality and reliable products. The threads on cylinder tubes and closure components are typically created by machining. Regarding production, since threads inevitably weaken the cylinder tube in the threaded area, the tube wall thickness of the cylinder tube must be increased to remove material and insert the threads, which is disadvantageous. Therefore, the tube wall thickness must be considerably large enough to absorb the forces during operation, especially those caused by the operating pressure of the fluid. The drawbacks of this solution are increased material consumption and an increase in the final weight of the working cylinder. From a manufacturing perspective, when a desired specific angular position of the closure member relative to each other or to the cylinder tube is required, aligning the threads of the closure member and the cylinder tube in a manner that allows for the application of the appropriate tightening torque during screwing is even more difficult. WO2021/089069A1 describes a solution that overcomes numerous shortcomings of the prior art. This solution discloses an operating cylinder in which both closure members are joined to a cylinder tube by a circumferential laser-welded seam. This solution presents production challenges, on the one hand, in that the laser-welded seam must have sufficient dimensions to absorb forces between the cylinder tube and the associated closure members even at maximum operating pressure, and on the other hand, the energy input per unit length during welding must be sufficiently low to avoid excessive thermal load on heat-sensitive components such as seals or guides. WO2021/089069A1 This is a schematic cross-sectional view of an operating cylinder, where the angle of cone, which has decreasing cone in the distal direction, is exaggerated.This is an enlarged cross-section of the joint section, with the conicity angle exaggerated.These are cross-sectional and enlarged cross-sectional views of the operating cylinder.This is a cross-sectional view and an enlarged cross-section of an operating cylinder in which the conicity increases distally.This is a cross-sectional view of the operating cylinder showing further coupling sections. Here, the same reference number in various figures refers to the same feature or component. Reference numbers are also used in the description if they are not shown in the relevant figure. Figure 1 shows a schematic cross-sectional view of one end of the operating cylinder 1. The operating cylinder 1 comprises a piston unit 2, a cylinder tube 3, and a closure member 4a. The cylinder tube 3 has two openings, one of which is closed by the closure member 4a, and the other by a further closure member 4b. In a fully assembled operating cylinder 1, the piston unit 2 slides through the further closure member 4b. In this exemplary embodiment, the piston unit 2 is designed in two parts: a piston rod and a piston. The piston unit 2 moves within the cylinder interior 6, forming the operating chamber 6.1. The closure member 4a is positioned at the end 5a of the cylinder tube. To assemble the operating cylinder 1, the cylinder tube 3 is pressed onto the closure member 4a. In this process, the joining path is overcome by force. For this purpose, the closure member 4a and the cylinder tube 3 are brought into contact with the chamfered inlet portion 4a.3 of the closure member and the chamfered inlet portion 5a.3 of the cylinder tube. The chamfered portions are used to more precisely position the joining partners 4a and 3 relative to each other. During the axial joining operation, the cylinder tube end portion 5a.1 slides on the axial portion 4a.1 of the closure member 4a. In this sliding process, the cylinder tube end portion 5a.1 is elastically expanded and conforms smoothly around the axial portion 4a.1 of the closure member 4a, in which case the axial portion expands distally by a cone angle α, resulting in this axial portion having a larger dimension in the proximal region 7a.1