MXPA99008167A - Process for manufacturing a switching valve - Google Patents

Abstract

A first sleeve (24) and a second sleeve (25) are placed around a shaft (23) at a predetermined axial distance from one another and are radially pressed. A thermoplastic material is injection-moulded around the shaft, between the first and second sleeves, forming a blade (30) with at least one recess (31). A sealing compound is injection-moulded around the blade to form a sealing lip (37) on the edge of the blade.

Description

PROCEDURE FOR THE MANUFACTURE OF A DISTRIBUTION VALVE FIELD OF THE INVENTION The invention relates to a method for manufacturing a distribution valve, which is arranged in particular in a suction tract of an internal combustion engine.

BACKGROUND OF THE INVENTION A distribution valve is known from WO 96/07022, which has a shaft and is configured in a stretched manner along the axis of rotation of the shaft. The distribution valve is arranged in an opening between two suction tubes of a vacuum cleaner and is rotatably received. The suction tubes branch out from a first manifold and open into cylinder inlets of the internal combustion engine. When the distribution valve is rotated in such a way that the opening is closed, the effective length of the tubes, ie the length in which the gas column vibrates in the suction pipe, matches the length of the tubes of aspiration of the first collector towards the inlets of the cylinders. When the distribution valve is rotated in such a way that the opening is open, the effective length of the suction pipes is in accordance with the distance from the opening to the cylinder inlets. Depending on the measurement values of the operating dimensions of the internal combustion engine, one of the two effective lengths of the suction tubes is chosen. In this way the load of the cylinders can be improved and, thus, increase the maximum torque. In the opening there are stops in which the dispensing valve rests when it is rotated in such a way that the opening is closed. From US Pat. No. 3,724,812 a dispensing valve is known which has a plate with a peripheral groove at its edges. In the plate there are notches, which communicate with the groove. A gasket is placed in the groove and notches.

OBJECTIVES AND ADVANTAGES OF THE INVENTION The objective of the invention is to provide a simple and reliable procedure for the manufacture of a distribution valve. The objective is achieved in accordance with the invention through the features of claim 1. The method according to the invention is characterized in that the shaft is coated in such a way with a thermoplastic, that a fin body is obtained. The latter is configured in such a way that it has at least one recess. A filling mass, with which the fin body is covered, penetrates the recess, so that a positive connection between the filling mass and the fin body is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS Advantageous embodiments of the invention are described in the subclaims. In the following, several embodiments of the invention are illustrated in more detail with reference to the schematic drawings. They show: Figure 1, an internal combustion engine. Fig. 2, a section of the internal combustion engine according to Fig. 1 along the cut line II-II '. Figure 3, a distribution valve manufactured with the method according to the invention. Figure 4, an amplification of a section of the distribution valve along the cut along the axis of rotation of the distribution valve. Figure 5, another amplification of a section of the distribution valve in a sectional drawing presentation. Figure 6, a section along a section line III-III 'of the internal combustion engine according to Figure 1. Figure 7, a first stage of work for the manufacture of the distribution valve. Figure 8, a second stage of work for the manufacture of the distribution valve. Figure 9, a third stage of work for the manufacture of the distribution valve.

DETAILED DESCRIPTION OF THE INVENTION The elements that have the same function and construction are identified with the same references in all the drawings. A vacuum 1 (Figure 1) of an internal combustion engine includes a suction connection piece 2, in which a throttle valve 3 is arranged. A first manifold 4 communicates through the suction connection piece 2 with the ambient air. The suction pipes 5, 6, 7, 8 go from the first manifold 4, passing through a second manifold 9, to the inlets of the cylinders 11, 12, 13, 14. These are arranged in an engine block 10. In In the area of the second manifold 9, distribution valves 20, 21, 22 are arranged, which are designed in a stretched manner and are rotatably mounted (FIG. 2). Depending on an operation dimension, such as, for example, a rotational speed N of a crankshaft not shown and / or an air mass flow and / or a suction pipe pressure, the distribution valves 20, 21, 22 are rotated to an open position or a closed position. In the open position of the distribution valves 20, 21, 22, the suction pipes 5, 6, 7, 8 communicate with each other through the openings, so that the effective suction pipe length, i.e. the area with continuous flow in the suction pipe, is in accordance with the distance of the openings to the inlets of the cylinders 11, 12, 13, 14. In the closed position of the distribution valves, they close the openings between the pipes suction 5, 6, 7, 8, so that the effective length of the suction pipes accords with the length of these from the first manifold 4 to the inlets of the cylinders 11, 12, 13, 14. The construction of the valves of distribution 20, 21, 22 is identical. The construction of the distribution valve 20 is described below by way of example. The distribution valve 20 (FIG. 3) has a shaft 23, which at a free end is bent perpendicularly. In this way, a simple rotation between the open position and the closed position in the installed state is possible by means of a linkage not shown, which is actuated by an adjusting member that is not shown either. The adjustment member is preferably a pressure capsule or an electric motor. On the shaft 23, at a predetermined distance, a first sleeve 24 and a second sleeve 25 are arranged. These are made with adjustment precision and serve to accommodate a bearing bushing 45, 46 (Figure 6). Preferably, a first and a second damping ring 28, 29 are additionally arranged on the shaft so that they rest on the first or even on the second sleeve 24, 25. The shaft 23 is connected positively to the shaft. body of fins 30. The positive union is achieved by stamped heels 23a, b. The shaft 23 and the fin body 30 are rigidly joined. The fin body 30 is additionally provided with recesses 31, 32, 33, 34. A filling mass is applied around the fin body 30 and configured in such a way that it forms a sealing lip 37 on the edge side of the valve of distribution, which in a closed state rests on a stop of the opening and, thus, closes it hermetically. In addition, the filling mass forms a first and a second sealing hood 39, 40, which are disposed at the opposite axial ends of the distribution valve 20, concentrically to the shaft 23. The sealing hoods 39, 40 are open respectively towards the opposite side to the distribution valve 20. On the side to which the distribution valve is directed, they are connected in positive union with the distribution valve.

Figure 4 shows a detailed amplification of the distribution valve 20 in a section along the axis of rotation of the distribution valve. The sealing hood 39 is conical. It is made of elastic material, preferably an elastomeric plastic. The sealing hood 39 can advantageously also be paraboloid, hemispherical or cylindrical. Figure 5 shows a preferred embodiment of the distribution valve 20 in a detailed amplification in a sectional presentation along the axis of rotation of the distribution valve 20. The sealing hood 39, in the form of a rim, goes beyond of the sealing lip 37. Figure 6 is a sectional presentation along a cutting line III-III 'according to Figure 1. In an opening 44 and a first bushing of the bearing 45 and a second bushing of the bearing 46 is the timing valve 20 is positioned. The first and second bearing bushes 45, 46 are preferably made of bronze and precisely fit with the first and second sleeves 24, 25. The distribution valve in Figure 6 is shown in the state open. The first and the second sealing hood 39, 40 are pressed against the first, or else, the second bearing bushing 45, 46, however, due to their elasticity and depending on the pressure, they can move outwards. In this way, with simple means, an axial seal of the distribution valve around the bearing bushing is achieved. By means of axial sealing, it is ensured that the pressure pulsations in the closed state of the distribution valve 20 are not transferred from the suction pipe 5 to the suction pipe 6 and vice versa. In addition, an axial play compensation with a swelling housing is effected by the first and the second sealing hood 39, 40. In this way it is ensured that the distribution valve 20 is housed in the center of the opening 44, independently of the temperature and manufacturing tolerances. The sealing hood 39, 40 further dampens the vibrations produced by the internal combustion engine and the noises generated by the first or second bearing bushes 45, 46 and the first, or second, sleeve 24, 25. The hood 39, 40 also greatly dampens an overflow noise produced by a rattle of the distribution valve 20 and the pressure differences between the suction pipes 5, 6. The above is a great advantage, because the overflow noise it becomes audible as an awkward whistle and given that stricter prescriptions are applied, which establish limit values for the amplitude of the sound waves generated by a vehicle. The manufacture of the distribution valve is described below. In a first manufacturing step, the shaft 23 (Figure 7) is perpendicularly layered at a free end and provided with printed heels 23a, b. The tree presents wide manufacturing tolerances in an economic mode. Processing of chip removal from the tree is dispensed with. Next, the first sleeve 24 and the second sleeve 25 are placed, at a predetermined axial distance, on the shaft 23 and compress radially. The sleeves are preferably formed with precise adjustment to the bearing bushings. In a second stage of work (Figure 8), the shaft 23 is placed in an injection tool and is coated in such a way with a thermoplastic between the first and the second sleeve 24, 25, that the fin body 30 is obtained. The printed heels 23a, b ensure that the fin body 30 is connected in positive connection with the shaft. The fin body has several recesses 31, 32, 33, 34. Thereafter, the fin body (FIG. 9) is covered in such a way with a filling mass, preferably made of elastomeric plastic, that on the edge side. A sealing lip is formed from the fin body. Preferably, the coating with the filling mass is carried out in such a way that the first and the second sealing hood 39, 40 are formed at the opposite axial ends of the fin body 30. The fin body 30 is completely covered with the filling mass. The sealing lip 37 and the first and second sealing hood 39, 40 are produced according to the above in an injection process. The recesses 31, 32, 33, 34 are preferably configured as elongated holes and, after coating, are filled with filling material. Thus, a positive connection with the fins body is guaranteed. The above has the advantage that no glue or fixative is required, a vulcanization can be dispensed with and the filling mass is well fixed, even when high friction forces act on it due to a passing fluid. The manufacturing process described has the advantage that the distribution valve can be manufactured in very few manufacturing stages and the distribution valve has a low weight but still a high mechanical resistance. In case the shaft is made of steel, a high rigidity of the distribution valve is guaranteed. In addition, the hermetic behavior of the distribution valve is optimized. The fin body can also be alternatively configured with three or four fins. The invention is not limited to the embodiments shown here.

Claims (6)

NOVELTY OF THE INVENTION Having described the above invention, it is considered as a novelty, and therefore, the content of the following is claimed as property: CLAIMS

1. A method for manufacturing a distribution valve, which has a fin body, which is connected to a shaft along its axis of rotation, wherein: - a first sleeve and a second sleeve are placed on the shaft , at a predetermined distance, and compress radially, - the tree is covered in such a way with a thermoplastic between the first and the second sleeve, that the fin body is formed, which has at least one notch, and - the fin body is covered in such a manner with a filling mass, that on the edge side of the fin body a sealing lip is formed.

2. A method according to claim 1, characterized in that the shaft is compressed in such a way at a point between the first and second sleeve, which has a stamped heel.

3. A method according to claim 1, characterized in that the fin body is covered in such a way with the filling mass that a first and a second hood are formed at the opposite axial ends of the fin body. obturation.

4. A method according to claim 1, characterized in that a damping ring is respectively placed on the shaft, on the side of the sleeve opposite the fin body, so that it rests on the sleeve.

5. A method according to claim 1, characterized in that the recess is configured as an elongated hole.

6. A method according to claim 1, characterized in that the shaft is elbowed at a free end.