DE102008047423A1 - Spring clamping device has two spring clamping elements for receiving coil spring which is fitted to suspension strut that is clamped, where drive unit is provided for displacement of spring clamping elements - Google Patents

Abstract

The invention relates to a spring tensioning device (1) with two spring tensioning elements (15a, 15b) for receiving a to a shock absorber (17) mounted to exciting coil spring (16) and with a drive unit (12) for displacing the spring clamping elements (15a, 15b) relative to each other along a spring tension direction (F). The spring tensioning device (1) according to the invention has a protective housing (3) which encloses the strut (17) with the helical spring (16) during tensioning of the helical spring (16). The invention also relates to a method for mounting a helical spring (16) on a suspension strut (17) by means of a spring tensioning device (1), comprising: positioning the tensioned helical spring (16) on the strut (17) between two spring tensioning elements (15a, helical spring (16) by moving the spring tensioning elements (15a, 15b) relative to each other and fixing the tensioned coil spring (16) on the strut (17), wherein during tensioning of the helical spring (16) the strut (17) with the coil spring (16) of a protective housing (3) of the spring tensioning device (1) is enclosed.

Description

The The present invention relates to a spring tensioning device with two Federspannelementen for receiving a mounted on a strut, too exciting coil spring, as well as with a drive unit for the displacement the spring tension elements relative to each other along a spring tension direction. The invention also relates to a method for mounting a coil spring on a strut by means of a spring tensioning device, comprising: Positioning the spring strut mounted to exciting coil spring between two spring tensioning elements of the spring tensioning device, tensioning the coil spring by moving the spring clamping elements relative to each other, as well as fixing the tensioned coil spring to the strut.

A spring tensioning device as described above, for example, from DE 298 16 410 U1 become known the company Hazet. The drive unit is designed there as a threaded spindle drive. To fix the coil spring to the shock absorber, first the shock absorber is installed in a motor vehicle. The coil spring is then tensioned by means of the spring tensioning device in the installed state in the motor vehicle by the spring tensioning elements are brought into engagement with the coil spring and subsequently driven with a wrench a drive polygon of the threaded spindle drive. After the coil spring has been tensioned to the desired length, it is fixed to the suspension strut by screwing a head onto the suspension strut.

The Clamping the coil spring by means of such a spring tensioning device involves considerable risks for the operator of the spring tensioning device connected, as this one possibly during the tensioning The coil spring occurring spring break injured by broken spring parts which can be due to the high on the coil spring acting forces of up to about 25 000 N with high acceleration remove from the break. Because of the big on the coil spring acting forces, the operator can also by protective clothing only insufficiently protected.

Object of the invention

It The object of the present invention is a spring tensioning device and a method of mounting a coil spring to a strut in that the operator when tensioning the coil spring is better protected. In particular, the operation of the Federspannvorrichtung be facilitated and possibly a quality control the coil spring during tightening done.

Subject of the invention

These The object is achieved by a spring tensioning device of the type mentioned, in which the Spring tensioning device has a protective housing, which the strut with the coil spring when tensioning the coil spring encloses. According to the invention, it is proposed make the tensioning of the coil spring in the protective housing, around the operator in the event of a spring break from broken parts of the Protect coil spring. The tensioning of the coil spring on the strut does not take place on the motor vehicle, but rather the coil spring in the spring tensioning device tensioned and on The strut is fixed before the strut with the mounted coil spring as a whole is installed in the vehicle.

The Protective housing is dimensioned so that it is sufficient Offers space for all common types of struts, each associated with one or more vehicle models. The protective housing encloses at least during tensioning (and Relaxing) of the coil spring the strut with the coil spring, but not necessarily complete. Rather, on the Provide a floor in the protective housing, if necessary, completely or be partially omitted if the spring tensioning device with the protective housing is placed on a substrate, the broken off parts of the coil spring withstands. It is understood that the type and thickness of the material of the protective housing must be chosen so that in a spring break strongly accelerated spring parts, the protective housing not can penetrate.

In a preferred embodiment, the protective housing has at least one protective hood which is preferably movable in the spring tension direction. The guard can be moved from a closed position, which it occupies during the tensioning of the coil spring, into an open position to position the coil spring for tensioning on the spring biasing elements or the strut with the tensioned coil spring out of the protective housing remove. For the movement, the guard can be designed to be pivotable, particularly preferably this is infinitely linearly displaceable. In particular, two protective hoods can be provided which can be telescopically displaced in the spring tension direction and cover each about half the length of the protective housing. In this case, by moving the protective covers, the entire longitudinal side of the protective housing for the operator accessible without the space required for the displacement of the protective hood space significantly above Longitudinal dimensions of the strut goes out.

In a further advantageous embodiment, the Protective housing at least one preferably transversely to the spring tension direction movable cover on. The movable cover can be used as a flap, d. H. be pivoted, or designed as a sliding door. In particular, two can be at opposite Side-mounted covers the protective housing in the transverse direction to lock.

Prefers have the guard and / or the cover respectively at least a handle to allow the operator to open or close the To facilitate protection housing.

In a particularly preferred embodiment is the Protective housing at least partially made of a transparent Material, in particular of plexiglass. Through the transparent material is the interior of the protective housing for the operator visible, so that the clamping process can be monitored and the operator can recognize when the coil spring enough is very tense to this by means of a final element on the strut to be able to fix. It is understood that to protect the Operator also the transparent material have a texture which ensures not too great material thickness, that broke the transparent material in a spring break Parts of the coil spring withstands; as such material is especially Plexiglas suitable.

Especially Preferably, the spring tensioning device comprises a frame with feet, where the protective housing is attached. The frame can made of a relatively light material, z. B. aluminum, to ensure that the weight of the spring tensioner remains small enough so that This can be worn by two or more people. To this end The spring tensioning device should not exceed a weight of approx. 60 kg. The feet usually have a length from a few centimeters to a safe state of the spring tensioning device to ensure. Also it is in case that the protective housing at least in a partial area not provided with a floor is favorable when the distance between the underside of the protective housing and the substrate, on which the spring tensioning device is turned off, so small is that no separated at a spring break parts of the coil spring between the underside of the protective housing and the substrate can pass through.

In an advantageous development is on the frame a plurality mounted by handles for transporting the spring tensioning device. With Help of the handles can the spring tensioning device of two or more people are transported to the respective place of use. The Dimensions of the spring tensioning device can in this case be chosen that this is mobile and transport over longer distances in the trunk of a car place finds, so that the spring tensioning device especially at Trial and test drives can be used.

In An advantageous embodiment is the drive unit for stepless displacement of the spring clamping elements in the spring tension direction designed. The drive unit can for this purpose in particular over have a threaded spindle and have a motor, which is infinitely variable by means of a suitable control. This allows a precise positioning of the Federspannelemente and thus improved operability of Spring tensioner.

Prefers the drive unit has a (infinitely variable) motor Gearbox on. The drive unit with the engine allows in contrast to In the prior art impact wrench used a precise Moving the spring clamping elements, what z. When positioning the coil spring is favorable to the Federspannelementen. Especially Also, the completion of the tightening process can be done while defined accidentally with the impact wrench over the coil spring the required for fixing the strut amount beyond is tense, which is particularly critical in terms of a spring break is. The engine can be realized in different ways, z. B. as a continuously variable electric motor or air motor, in the latter case, a pneumatic transmission is used.

Particularly preferably, the spring tensioning elements are designed for receiving clamping disks, against which in each case a spring coil of the coil spring rests. The clamping disks can hereby z. B. as in the DE 20 2006 014 999 U1 be trained by the company Hazet. It is understood that clamping discs from other manufacturers, eg. B. of the company Klann, can be used in the spring tensioning device according to the invention. In any case, different pulley types can be accommodated by the spring biasing members adapted to the respective coil spring type of the strut of a particular car model.

In an advantageous embodiment, the spring tensioning device comprises a measuring device for receiving a characteristic curve when tensioning the coil spring. As a characteristic curve, the relationship between the applied force and the displacement travel of the spring tensioning elements in the spring tension direction is typically measured, for which also the distance of the spring clamping elements is determined at the beginning of the clamping process. By comparing the recorded characteristic, ie the force-displacement dependence of the coil spring with characteristics characteristic of the corresponding spring type, a defect on the coil spring can be detected. If the characteristic line "online", ie compared with characteristic curves when tensioning the coil spring, an impending spring break may possibly be detected and the tensioning of the coil spring can be canceled before the spring break.

Prefers The spring tensioning device comprises an interface for transmission of measured data to an external evaluation device. With the external Evaluation device (eg a laptop) can provide measurement data, in particular the recorded characteristic, with characteristic Characteristics are compared and z. B. an acoustic or optical Signal is output to the operator if the comparison results, that is to be expected with a spring break. It is understood that when evaluating the recorded characteristic at or after completion the tensioning process carried out a check can be, whether the coil spring meets the quality requirements equivalent. It is further understood that the evaluation device can also be integrated into the spring tensioning device, and in particular on the spring tensioning device, a display device for display of measured data or other data, e.g. B. on the operating condition of Spring tensioning device may be provided.

In a particularly advantageous embodiment comprises the Federspannvor direction at least one operating device for the drive device, in particular a manual device or a footswitch device. The operating device allows a continuous displacement of the spring clamping elements, where appropriate between two or more different shift speeds selected can be. Also a stepless variation of the displacement speed with the help of a continuously adjustable control element is possibly possible. At the spring tensioning device, a switch between manual and foot operation to be provided. The foot switch device is especially when positioning the coil spring on the spring biasing elements advantageous since the operator hands free in this case has to correct the position of the coil spring if necessary.

In a particularly advantageous embodiment, the Protective housing at least one contact switch, which is activated when closing the protective housing. The drive unit of the spring tensioning device can with the contact switch communicate with and monitor, with the engine for tensioning or relaxing the coil spring first is released when the contact switch is activated, d. H. when the protective housing is closed.

The Invention is also realized in a method of the beginning mentioned type, in which when tensioning the coil spring, the strut with the coil spring of a protective housing of the spring tensioning device is enclosed. When mounting the coil spring on the strut A spring break usually occurs during tensioning the coil spring on. For a breakage of the coil spring in the tensioned state, on the other hand, there is only a very small probability. According to the invention, therefore, the tensioning of the coil spring from Installation location on the motor vehicle in the protective housing of the spring tensioning device misplaced, from which the strut with the tensioned coil spring safe removed and subsequently installed as a whole on the vehicle can.

In An advantageous variant is to position the coil spring and for fixing the coil spring, the protective housing open. Fixing the coil spring with open Protective housing is safe for the operator, there - as stated above - usually no spring break occurs on the tensioned spring.

In a particularly preferred variant is during tensioning the coil spring recorded a characteristic of the coil spring. As shown above, the characteristic with for the used Spring type characteristic curves are compared to a to recognize impending spring break and / or quality to evaluate the coil spring.

Further Advantages of the invention will become apparent from the description and the Drawing. Likewise, the above and the even more features listed in each case or to several in any combination use. The shown and described embodiments are not to understand as a final list, but rather have exemplary character for the description the invention.

It demonstrate:

1a , b are perspective views of an embodiment of a spring tensioning device according to the invention with closed or without protective housing, and

2a -C side view of the spring tensioning device according to the invention along or transverse to the spring tension direction with closed protective housing and a plan view of the spring tensioning device without protective housing.

1a such as 2a , b show a spring tensioning device 1 with a frame 2 made of aluminum, on which a protective housing 3 is attached, the two in the longitudinal direction of the frame 2 sliding protective covers 4a . 4b comprising, telescopically in the longitudinal direction of the frame 2 can be moved. At opposite ends of the spring tensioning device 1 are on the frame 2 continue two in the transverse direction of the frame 2 sliding sliding doors 5a . 5b appropriate. For the protective hoods 4a . 4b as well as the sliding doors 5a . 5b serves the frame 2 as a guide to these with the help of handles 6a . 6b . 7a . 7b to slide into the desired position. At the desired position, the protection hoods can 4a . 4b or the sliding doors 5a . 5 by means of one of the handles 6a . 6b . 7a . 7b attached latching mechanism can be locked by one on the handles 6a . 6b . 7a . 7b positioned latch with one on the frame 2 attached rack is engaged. The frame 2 also has adjustable feet 8a -D on to the spring tensioner 1 to park on a stable surface.

The protective housing 3 also includes an intermediate wall 9 which several on the frame 2 arranged electronic or mechanical components from the interior of the protective housing 3 separates, cf. 2c , Initially, this is a control cabinet 10 to the power supply, whose side wall is part of the partition 9 forms and that via a servo inverter 11 with a worm geared motor 12 communicates. In 2c also visible are four attached to the frame carrying handles 13a -D for transporting the spring tensioning device 1 , which can be operated both mobile and stationary.

The worm geared motor 12 serves to drive one in the protective housing 3 in a guide tube 14 (see. 1b ) arranged threaded spindle, which is a relative movement of two spring clamping elements coupled to the threaded spindle 15a . 15b , which are formed in the form of grippers, effected in a spring tension direction F. The spring tensioning elements 15a . 15b are each designed to receive a (not shown) clamping disc, on which a spring coil of a coil spring 16 can be planted. Since the clamping disks are not fixed to the spring clamping elements 15a . 15b are connected, suitable for each coil spring type suitable clamping discs can be selected. The coil spring type specifies characteristics such as diameter, spring pitch, spring length, etc. of the coil spring, which depend on the vehicle type in which the coil spring is to be installed.

Subsequently, the clamping operation of the coil spring or the assembly of the coil spring to a strut 17 with the help of the spring tensioning device 1 described in detail:
First, the on the strut 17 attached, too exciting coil spring 16 between the two spring clamping elements 15a . 15b the spring tensioning device 1 positioned, cf. 1b , at which on the representation of the protective housing 3 was waived. After positioning, the protective housing becomes 3 closed, ie the protective hoods 4a . 4b or the sliding doors 5a . 5b be in the in 1a shown, closed position. The protective housing 3 encloses the spring clamping elements 15a . 15b as well as the coil spring 16 with the strut 17 from five sides, ie the protective housing 3 is only open in the floor area. Because the spring tensioning device 1 is usually placed on a substrate made of a material that resists a spring break, the operator is at a fraction of the coil spring 16 during the tensioning or relaxing process through the protective housing 3 and protected the underground. The protective housing 3 can also be whole or as in 1b shown in a partial area with a floor 18 be provided so that the protective housing 3 the coil spring 16 if necessary completely enclosed by all sides.

When moving the sliding doors 5a . 5b as well as the protective hoods 4a . 4b can on the frame 2 (not shown) contact switches are activated as soon as the sliding doors 5a . 5b or the protective hoods 4a . 4b take a closed position. In a control device (not shown), the contact switches can be monitored and the movement of the spring tensioning elements 15a . 15b or the activation of the worm geared motor 12 for tensioning or relaxing the coil spring 16 only be released when all contact switches are activated, ie when the protective housing 3 closed is.

In the closed protective housing 3 becomes the coil spring 16 by moving the spring clamping elements 15a . 15b clamped relative to each other in the spring tension direction F, wherein via the servo-inverter 11 a stepless control of the engine 12 and thus a stepless displacement of the spring clamping elements 15a . 15b he follows. To control the sliding operation, the operator has a handset device 20 and a footswitch (not shown). The handset device 20 is with the frame 2 releasably connected. Will the handset device 20 from the frame 2 solved, this is a cable connection with the spring tensioning device 1 in connection. The handset device 20 has four buttons that indicate a movement of the spring loaded elements 15a . 15b in the spring tension direction F to each other or away from each other with two different speeds (slow / fast) effect. A switch on the Handtasteinrichtung 20 allows switching between manual mode and foot operation with the footswitch connected to the control box 10 the spring tensioning device 1 Connected via a cable and has the two pedals, which is an operation of the engine 12 allow at slow speed. The foot operation is for the operator in particular when positioning the coil spring 16 on the spring clamping elements 15a . 15b advantageous.

Indicates the coil spring 16 the desired voltage, the operator can the protective housing 3 open and the cocked coil spring 16 fix it by placing an attachment on the strut 17 is screwed on. Subsequently, the coil spring with closed protective housing 3 relaxed. After that, the strut becomes 17 with the mounted coil spring 16 from the protective housing 3 removed and can be mounted in a motor vehicle.

During the clamping process, by means of a measuring device 21 (see. 2c ) the spring characteristic of the coil spring 16 be determined by the on the coil spring 16 applied force or that of the engine 12 exerted torque as a function of the position of the threaded spindle, ie the relative position of the spring clamping elements 15a . 15b in Federspannrichtung F is determined. The spring characteristic determined in this way can be provided via a serial or another suitable interface 22 to an external evaluation unit (not shown), e.g. As a computer, are transmitted and compared there with known, characteristic of the type of spring used spring characteristics. Will this comparison during the tensioning of the coil spring 16 carried out, so may possibly early on a defect in the coil spring 16 recognized and prevented in this way a spring break. Also, a significant deviation of the spring characteristic from a predetermined tolerance range can cause the clamping operation is canceled and the non-standard coil spring is replaced before the completion of the clamping process by another coil spring.

Overall, with the help of the mobile spring tensioning device described above 1 the assembly or disassembly of a coil spring 16 on a strut 17 inside the protective housing 3 controlled, carried out quickly and safely. It is understood that the spring tensioning direction F does not necessarily have to be horizontal, but the spring tensioning device can also be designed so that the spring tensioning direction runs in a different direction, for. B. in the vertical direction.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 29816410 U1 [0002]
• - DE 202006014999 U1 [0015]

Claims (17)

Spring tensioning device ( 1 ) with two spring clamping elements ( 15a . 15b ) for receiving a suspension strut ( 17 ), to exciting coil spring ( 16 ), as well as with a drive unit ( 12 ) for the displacement of the spring clamping elements ( 15a . 15b ) relative to each other along a spring tension direction (F), characterized in that the spring tensioning device ( 1 ) a protective housing ( 3 ), which the strut ( 17 ) with the coil spring ( 16 ) when tensioning the coil spring ( 16 ) encloses. Spring tensioning device according to claim 1, wherein the protective housing ( 3 ) at least one preferably in Federspannrichtung (F) movable protective hood ( 4a . 4b ) having. Spring tensioning device according to claim 1 or 2, wherein the protective housing ( 3 ) at least one preferably transversely to the spring tension direction (F) movable cover ( 5a . 5b ) having. Spring tensioning device according to one of claims 2 or 3, in which the protective hood ( 4a . 4b ) and / or the cover ( 5a . 5b ) at least one handle ( 6a . 6b ; 7a . 7b ) exhibit. Spring tensioning device according to one of the preceding claims, in which the protective housing ( 3 ) consists at least partially of a transparent material, in particular Plexiglas. Spring tensioning device according to one of the preceding claims, further comprising a frame ( 2 ) with adjustable feet ( 8a -D) where the protective housing ( 3 ) is attached. Spring tensioning device according to claim 6, in which on the frame ( 2 ) a plurality of handles ( 13a -D) for transporting the spring tensioning device ( 1 ) is attached. Spring tensioning device according to one of the preceding claims, in which the drive unit ( 12 ) for stepless displacement of the spring clamping elements ( 15a . 15b ) is designed in Federspannrichtung (F). Spring tensioning device according to one of the preceding claims, in which the drive unit ( 12 ) has a motor with gear. Spring tensioning device according to one of the preceding claims, in which the spring tensioning elements ( 15a . 15b ) are formed for receiving clamping disks, on each of which a spring coil of the coil spring ( 16 ) is present. Spring tensioning device according to one of the preceding claims, further comprising a measuring device ( 21 ) for receiving a characteristic curve when tensioning the coil spring ( 16 ). Spring tensioning device according to one of the preceding claims, further comprising an interface ( 22 ) for the transmission of measurement data to an external evaluation device. Spring tensioning device according to one of the preceding claims, further comprising at least one operating device for the drive device ( 12 ), in particular a handset device ( 20 ) or a footswitch device. Spring tensioning device according to one of the preceding claims, in which the protective housing ( 3 ) has at least one contact switch, which when closing the protective housing ( 3 ) is activated. Method for mounting a coil spring ( 16 ) on a strut ( 17 ) by means of a spring tensioning device ( 1 ), comprising: positioning the spring leg ( 17 ), to exciting coil spring ( 16 ) between two spring clamping elements ( 15a . 15b ) of the spring tensioning device ( 1 ), Tensioning the coil spring ( 16 ) by moving the spring clamping elements ( 15a . 15b ) relative to each other, as well as fixing the tensioned coil spring ( 16 ) on the strut ( 17 ), characterized in that when tensioning the coil spring ( 16 ) the strut ( 17 ) with the coil spring ( 16 ) of a protective housing ( 3 ) of the spring tensioning device ( 1 ) is enclosed. Method according to claim 15, in which for positioning the coil spring ( 16 ) and for fixing the coil spring ( 16 ) the protective housing ( 3 ) is opened. Method according to claim 15 or 16, wherein during the tightening of the helical spring ( 16 ) a characteristic of the coil spring ( 16 ) is recorded.