Pressure piece for tensioning rails for venting and oil spraying of chains

Abstract

Pressure piece (1) for fastening to a tensioning rail (2) of a traction drive, with a fastening section (8) which is prepared for entering into a connection with the tensioning rail (2) and a contact section (7) which is prepared for coming into contact with a tensioner, characterized in that a plurality of passages (9) for fluid conduction which completely penetrate said contact section are provided in the contact section (7), wherein the passages (9) are arranged one behind the other in the longitudinal direction of the pressure piece (1), wherein 4, 5, 6 or more passages (9) are arranged and / or that the passages (9) extend in the longitudinal direction over the entire length of the pressure piece (1).

Description

Field of the invention

[0001] The invention relates to a pressure piece for fastening to a tensioning rail of a traction mechanism drive, with a fastening section which is prepared to form a connection with the tensioning rail and a contact section which is prepared to come into contact with a tensioner, for example a hydraulic piston of a traction mechanism tensioner.

[0002] Such pressure pieces are known, for example, from EP 2 021 654 B4. This document discloses a tensioning rail with a channel device in a pressure body. In particular, it presents a tensioning rail for a chain drive, in particular for a timing chain drive of an internal combustion engine, comprising a base body and a pressure body connected to the base body, which provides a pressing area for pressing on a chain tensioner. What is particularly highlighted in this older patent specification is that a pressing surface of the pressure body, which during use faces the chain tensioner and comes into contact with it, is provided with a channel device designed as a groove and provides ventilation. The channel device is designed as a groove and extends lengthwise over the entire pressing surface. The pressure body can be locked to the base body. The pressing surface can be concave or convex.The pressure hull is also made of a material selected from the group of wear-resistant materials, which is particularly dampening and has a low coefficient of friction. The width of the channel device essentially corresponds to the diameter of a chain tensioner's vent opening.

[0003] Such a thrust piece is used in a traction drive of a motor vehicle engine, such as a car, a truck or another commercial vehicle, in particular in the timing drive of the internal combustion engine.

[0004] Such a printed document can, for example, still be found in the subsequently published DE 10 2012 021 243 A1.

[0005] The use of pressure pins or caps on a tensioner piston is also known (alternatively).

[0006] JP 2003 - 329 092 A also discloses a T-shaped pressure piece which has an internal oil channel, wherein the T-shaped pressure piece is inserted into an oil channel of a base body.

[0007] However, existing solutions have disadvantages. For example, oil injection, i.e., providing additional chain lubrication by applying oil to the chain tensioner, is not possible. In some cases, venting from the center of the tensioner piston is also not possible, which leads to more expensive and complex cross-hole drilling in the tensioner piston.

[0008] The object of the present invention is to eliminate these disadvantages and to supply hydraulic fluid, such as oil, to the chain via the tensioner piston and through the tensioning rail. However, wear at the pressure point of the tensioning rail should remain low. Disclosure of the invention

[0009] This object is achieved according to the invention in a generic device with the features of claim 1. A plurality of completely penetrating passages for fluid conduction are provided in the contact section. The passages are arranged one behind the other in the longitudinal direction of the pressure piece, approximately 4, 5, 6 or more passages. The contact section corresponds to a pressing area and / or a pressing surface for a tensioner piston.

[0010] This prevents wear on the tensioning rail, which, for example, has an aluminum support body. Oil can still be used to lubricate the chain and can be directed accordingly. For this purpose, the pressure piece is inserted between the tensioner piston and the tensioning rail.

[0011] If the passages are always equally spaced from each other, a consistent oil flow characteristic is achieved. The large number of passages also allows for the largest possible oil volume to pass through.

[0012] Advantageous embodiments are claimed in the subclaims and are explained in more detail below.

[0013] An advantageous embodiment is also characterized in that the passage opens into a groove on a side facing away from the clamp. In other words, the groove is thus formed on the side facing away from the pressing surface or the pressing area, for example, by machining, such as milling, or non-machining, such as forming.

[0014] In order to ensure that the flow of hydraulic fluid is particularly undisturbed, it is advantageous if a passage is designed as a preferably circular hole and has a diameter that corresponds to between 0.7 and 0.3 times, particularly preferably 0.5 times, the thickness of the pressure piece.

[0015] It has proven advantageous to have a convex or spherical but smooth surface on the contact side facing the clamp. This simplifies production and optimizes the contact for different positions of the clamping rail relative to the clamp.

[0016] It is advantageous for the load-bearing capacity of the pressure piece if stiffening webs are formed in the contact section.

[0017] It is advantageous if each stiffening web extends transversely to the longitudinal direction of the pressure piece. Six stiffening webs are advantageously provided on each side of the pressure piece, for example, to divide a large transverse passage. Of course, more or fewer stiffening webs can also be used.

[0018] A particularly advantageous embodiment is also characterized in that an inner diameter of the passage / passage is between 50% and 150% larger than a vent opening, such as a bore, in the piston, wherein the passage / passage is aligned / arranged in the immediate vicinity of the vent opening, such as bordering it.

[0019] The invention also relates to a tensioning rail with a preferably clipped-in or clipped-on pressure piece of the type according to the invention.

[0020] The invention also relates to a traction mechanism drive with a tensioning rail according to the invention and a tensioner that can be brought or is brought into contact with the contact side of the pressure piece.

[0021] In other words, a pressure piece is presented that can be manufactured from plastic. Advantageously, at least one type of polyamide, such as PA66 or PA46, is used, with glass fibers being used for stiffening.

[0022] On one side, the pressure piece rests flat against a support body, while on the opposite side it rests against a piston, such as the hydraulic piston of a tensioner. The contact surface between the hydraulic piston and the pressure piece should be as convex as possible to keep the pressure in this area as low as possible.

[0023] Holes are provided in the center of the pressure piece for venting and for the passage of oil. The diameter of the holes should be between 50% and 150% larger than a hole in the piston. This ensures that air and oil can be safely drained away if the rail is tilted to a certain extent. On the back, i.e. on the side that is in contact with the rail or the supporting body of the clamping rail, the holes have a groove. This groove is used to vent the tensioner or to drain the oil from the tensioner, i.e. through the hydraulic piston. This has the advantage that a cross-bore in the piston can be omitted, thus reducing machining costs. In this design, holes are used instead of a through groove. This has the advantage that the pressure piece is not weakened too much in the center and has a connection between the two outer pressure surfaces across the entire central area.This ensures maximum rigidity in the pressure piece.

[0024] The pressure piece is snapped into the support body of the tensioning rail using snap hooks that snap outwards. This has the advantage of creating a contour in the support body between the two snap hooks, allowing oil to flow to the chain. This provides chain lubrication and cooling.

[0025] The invention is explained in more detail below with the aid of a drawing in which a first embodiment is explained in more detail.

[0026] They show: Fig. 1 a singularly illustrated pressure piece according to the invention in perspective view, from the side of a hydraulic piston of a tensioning device, Fig. 2 another perspective view of the printed piece from Fig. 1 from the side of the tensioning rail, Fig. 3 a top view of a contact section of the pressure piece from the Fig. 1 and Fig. 2, Fig. 4 a view from below of the side of the pressure piece facing the clamping rail of the Fig. 1 to 3, Fig. 5 a rotated view of the side of the pressure piece, Fig. 6 a side view of the snap hook of the pressure piece, Fig. 7 a longitudinal section through the pressure piece, Fig. 8 a side view of a clamping rail with inserted pressure piece, Fig. 9 a view from below, i.e. from the hydraulic piston side of the tensioning device, onto the tensioning rail Fig. 8 with inserted pressure piece, Fig. 10 a section through the tensioning rail of the Fig. 8 and Fig. 9 with inserted pressure piece.

[0027] The figures are merely schematic and serve only to clarify the invention. The same elements are designated by the same reference numerals.

[0028] In Fig. 1 shows a pressure piece 1 according to the invention. The pressure piece 1 is inserted into a Fig. 8 to 10. The pressure piece 1 is formed from two integrally connected sections, namely a contact section 7 and a fastening section 8. The fastening section 8 forms snap hooks 3. The pressure piece 1 has snap hooks 3 on opposite sides. The pressure piece is fastened to the tensioning rail 2 with these snap hooks 3.

[0029] The contact section 7 has a surface facing a hydraulically extendable tensioner piston, which, since it comes into contact with the latter, is referred to as contact surface 6.

[0030] Along a longitudinal axis 4 of the pressure piece 1, a Fig. 2 clearly visible groove 5 is formed on the back of the contact section 7.

[0031] The snap hooks 3 are part of a fastening section 8. The contact section 7 and the fastening section 8 together form the pressure piece 1 as an integral component. Passages 9 are formed orthogonally to a plane containing the longitudinal axis 4 and through which a part of the contact surface 6 penetrates. On the clamping rail side 10, the passages 9, designed as bores 11, open into the groove 5. This is also shown in Fig. 4 clearly visible.

[0032] Between the holes 11 stiffening webs 12 are formed, as can be seen particularly well in the Fig. 3 and Fig. 7. While in the Fig. 3 to 7 the printed piece is shown in isolation, it is in the Fig.8 to 10 in the inserted state in the tensioning rail 2, which, in addition to a support body 13, also has a sliding coating 14. The support body 13 is made of an aluminum alloy, whereas the sliding coating 14 is made of plastic and has particularly good sliding properties. List of reference symbols 1 pressure piece 2 clamping rails 3 snap hooks 4 Longitudinal axis 5 grooves 6 Contact surface / contact side 7 Annex Section 8 Fastening section 9 Passage 10 Clamping rail side 11 Hole 12 stiffening bar 13 supporting bodies 14 Sliding coating

Claims

[1] Pressure piece (1) for fastening to a tensioning rail (2) of a traction drive, with a fastening section (8) which is prepared to form a connection with the tensioning rail (2) and a contact section (7) which is prepared to come into contact with a tensioner, characterized by that a plurality of passages (9) for fluid conduction are provided in the contact section (7), said passages (9) completely penetrating said contact section, wherein the passages (9) are arranged one behind the other in the longitudinal direction of the pressure piece (1), wherein 4, 5, 6 or more passages (9) are arranged and / or that the passages (9) extend in the longitudinal direction over the entire length of the pressure piece (1). [2] Pressure piece (1) according to claim 1, characterized by that the passages (9) open into a groove (5) on a side (10) facing away from the tensioner. [3] Pressure piece (1) according to one of claims 1 to 2, characterized bythat the passages (9) are each designed as a preferably circular hole and have a diameter which corresponds to between 0.7 and 0.3 times, particularly preferably 0.5 times, the thickness of the pressure piece (1). [4] Pressure piece (1) according to one of claims 1 to 3, characterized by that one side of the contact surface facing the tensioner is convex. [5] Pressure piece (1) according to one of the preceding claims, characterized by that an inner diameter of the passages (9) is between 50% and 150% larger than a vent opening in the piston of a hydraulic piston of the tensioner. [6] Clamping rail (2) with a pressure piece (1) according to one of claims 1 to 5. [7] Traction mechanism drive with a tensioning rail (2) according to claim 6 and a tensioner which can be brought or is brought into contact with the contact side (6) of the pressure piece (1).

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