FR2703427A1 - Pipe clamp. - Google Patents

Abstract

A pipe clamp (7) for securing in groups of several injection pipes (2, 3, 4, 5) of a combustion engine, in particular a diesel engine of a passenger car, is formed to reduce the costs associated with its manufacture and assembly, formed in such a way that, in section, it only partially surrounds each of the injection ducts and that it is fixed thereto only by surface adhesion.

Description

1 2703427

  The invention relates to a pipe clamp of the type cited in the preamble to the

claim 1.

  Such pipe clamps known in particular from patent DE-34 41 302 are used for several reasons for the reciprocal mechanical connection of injection pipes of internal combustion engines. Thus, such injection pipes are subjected to strong vibrations which are created by the process of jerky injections and by the relative movements between the injection pumps and the nozzles. This leads to a significant alternating bending stress, under the effect of which thin injection pipes can break, especially

  behind the fittings at the clamping points, but also in other places.

  To avoid this, the injection pipes are generally mechanically fixed to each other by a whole series of pipe clamps, which are positioned in such a way that they dampen the vibrations of the pipes below the critical stress limit. Another point of view is that, with the help of pipe clamps, already before their mounting on combustion engines, the injection pipes are mounted in advance, according to their future laying geometry. This is done in such a way that the injection pipes can be brought together in a complete group to the place of installation and that they can be connected to it at the level of the cylinder block without further

  adaptation work, on the one hand at the injection pump and on the other hand at the nozzles.

  To solve these problems, known pipe clamps have so far been developed so that in section they completely surround the pipes and grip them as tightly as possible. For this purpose, known pipe clamps have an element of receiving and a stirrup hinged thereon, said stirrup can be opened for mounting the pipe clamp and, after introduction of the pipes into corresponding recesses of the receiving member, it can be closed again To obtain the effect clamping required, the free end of the bracket must be connected, either by a clamping screw, or by means of a stop device to the area of the receiving element facing it in such a way a large clamping force is applied to the pipes In addition, the known pipe clamps must be made of metal or of high quality synthetic material, that is to say of materials of great resistance. nce, which are capable of receiving the above-mentioned forces and of acting as a vibration damper This has the consequence that the manufacture and assembly of collars for known pipes entail very high costs On the contrary, the problem underlying the invention is to improve a pipe clamp of the aforementioned type so that the costs associated with the

  manufacturing and its assembly can be considerably reduced.

  To solve this problem, the invention provides the characteristics summarized in claim 1 These measures are based on the observation that there are now injection pipes for which vibration damping plays only a very secondary role. , are for example known from patent DE-38 01703, fuel injection conduits with a pressurized pressure connection which consist of hard white drawing steel and for which only the sealed area of the pressure connection, with which this comes to rest, in the assembled state, on the hollow cone surface of the complementary part, is inductively brought to red until softening after the discharge, while all the other parts of pipes keep their great resistance . In the most advantageous case, that is to say in particular for diesel engines of passenger cars operating normally, the damping of vibrations is absolutely no longer necessary. Here, the pipe clamps according to the invention, including preferably only one is used per group of conduits, the main purpose of which is to fix the injection conduits to one another to form a group of conduits assembled in advance, said group of conduits being able as a whole, prepared , stored, transported and mounted on the engine After mounting, the hose clamp has fulfilled its task and can be removed from the injection pipes, either immediately or during the next maintenance This is easily achievable since in section, the pipe clamp only partially surrounds each injection pipe. On the other hand, the surface adhesion provided according to the invention between the pipes and the pipe clamp is sufficient. t large to ensure between the preliminary and final assemblies, that the pipes are securely fixed to each other and that they are held in their position

  relative required for simple final assembly.

  In particular, fixing by gluing, soldering, welding, etc., preferably provided between the pipes and the pipe clamp, ensures that the pipes cannot move at all so that the accuracy of the connection dimensions of the group of pipes is preserved. However, after final assembly, a small separation of pipes is possible when cutting, cutting, tearing off or the like for the clamp.

pipes, like dominoes.

3 2703427

  Since the pipe clamp according to the invention should not precisely define the relative position of the pipes until the final assembly, that is to say only during a relatively short period of time, during which, unlike after mounting in the vehicle, neither strong shocks nor high temperature stresses occur, the pipe clamp can be made from a low-value plastic material having a relatively low resistance In particular, it is possible to

  here use recyclable waste or synthetic materials.

  The invention will hereinafter be described with the aid of an exemplary embodiment with reference to the drawings, in these drawings: FIG. 1 shows a top view of a portion of a group of injection conduits, the pipes are fixed to each other by a pipe clamp according to the inventon and Figure 2 shows a section of the group of pipes of Figure 1 according to the

line 11-11.

  In Figures 1 and 2 is shown a group of injection pipes 1 which has four injection pipes 2, 3, 4, 5, extending over the portion shown in a plane, parallel to each other and being fixed to each other in all by a single pipe clamp 7 The pipe clamp produced in one piece has a number of receiving blocks 10, 11, 12, 13 corresponding to the number of pipes to be fixed together, said receiving blocks 10 , 11, 12, 13 have an approximately square section and

  each present on its surface located at the top in FIG. 2, with a recess of semi-section

  cylindrical extending over its entire length and the diameter of which is adapted to the outside diameter of the pipes 2, 3, 4 or 5 to be received The length of the receiving blocks 10 to 13 is chosen so that the surface adhesion existing between the lateral surface of each pipe 2 to 5 and the internal surface of the recess receiving the pipe can create a holding force large enough to ensure the chosen relative position of pipes 2 to 5 between the time of their preliminary assembly, where they are fixed together by means of the pipe clamp 7, until they are mounted in the vehicle. This surface adhesion can be achieved according to the invention by gluing, welding, brazing or any other

equivalent means.

  As can be seen more particularly in FIG. 2, each of the receiving blocks 10 to 13 surrounds the circumference of the corresponding pipe 2 to 5 only up to half, so that no clamping or clamping force n 'is exercised It is quite possible to provide a less ample wrapping of pipes 2 to 5, as long as the contact surfaces between each receiving block 10 to 13 and the corresponding pipe 2 to 5 are large enough to exercise for fixing choose holding forces

described above.

  The receiving blocks 10 to 13 are connected together to form a block, by crosspieces 14, 15 and 16, which have a reduced thickness so that the pipe collar 7 can easily be separated at these crosspieces. cross members 14, 15 and 16 is chosen such that the pipe clamp 7 has on the whole a sufficient rigidity to ensure the positioning accuracy of the pipes 2 to 5 required for simple mounting of the group of pipes, even when for

  a group 1, a single pipe clamp 7 is used.

2703427

Claims (9)

Claims:   1. Pipe clamp for group fixing of several injection pipes of an internal combustion engine, in particular of a passenger car diesel engine, characterized in that in section, the pipe clamp (7) only partially surrounds each of the injection pipes (2, 3, 4, 5) and is fixed to them only by surface adhesion. 2. Pipe clamp according to claim 1, characterized in that by group of   only one pipe clamp (7) is provided.   3 pipe clamp according to claim 1 or claim 2, characterized in that the injection pipes (2, 3, 4, 5) are respectively formed from a hard white steel pipe with a pressure connection upset, for which only the area in which the sealed surface of the pressure fitting comes to rest on the hollow cone surface of the complementary part, is brought to red until softening after repression.   4. Pipe clamp according to one of claims 1 to 3, characterized in that   surface adhesion is obtained by bonding.   5 Pipe clamp according to one of claims 1 to 3, characterized in that   surface adhesion is obtained by welding or stirring.   6. Pipe clamp according to one of claims 1 to 5, characterized in that the   pipe clamp (7) does not surround each of the injection pipes (2, 3, 4, 5) at the   maximum than up to half the circumference.   7. Pipe clamp according to one of claims 1 to 6, characterized in that the   pipe clamp (7) has a number of receiving blocks (10, 11, 12, 13) corresponding to the number of injection pipes (2, 3, 4, 5) present per group (1), each of which partially surrounds one of the injection conduits (2, 3, 4, 5) and in that the receiving blocks (10, 11, 12, 13) are interconnected to form a block, by   sleepers (14, 15, 16) of reduced thickness. 6 2703427   8. Pipe clamp according to any one of the preceding claims,   characterized in that the pipe clamp (7) is formed and fixed to the injection pipes (2, 3, 4, 5) in such a way that it keeps them in a predetermined position   with the precision required for simple assembly.   9. Pipe clamp according to any one of the preceding claims,   characterized in that the pipe clamp (7) consists of synthetic material of low resistance.