Floor conveyor with a hydraulic fluid tank

Description

[0001] The invention relates to an industrial truck with a hydraulic fluid tank. Such tanks hold hydraulic fluid for operating the hydraulic components of the industrial truck, in particular a hydraulically driven lifting device. The hydraulic fluid tank must offer a high degree of protection against unwanted leakage of hydraulic fluid and, given the accelerations and vibrations that occur during operation of the vehicle, be securely mounted in the industrial truck and protected from external influences.

[0002] The hydraulic fluid tank has a considerable volume that holds the hydraulic fluid and is usually enclosed by a relatively thin wall. Hydraulic lines connected to the hydraulic fluid tank are sealed against the wall.

[0003] Two different solutions have been developed for mounting such hydraulic fluid tanks in industrial trucks. The first solution involves attaching the hydraulic fluid tank to a support of the industrial truck using a clamp or similar bracket. The clamp or other bracket encloses part of the hydraulic fluid tank and clamps it to the support. This fixes the hydraulic fluid tank relative to the support, preventing it from slipping during operation of the industrial truck.

[0004] In a second solution, the hydraulic fluid tank is at least partially surrounded by a dedicated receiving space of the industrial truck, with spacers, for example in the form of foam rubber plates, arranged between the inner sides of the receiving space facing the hydraulic fluid tank and the hydraulic fluid tank. This secures the hydraulic fluid tank against slipping in the receiving space.

[0005] From DE 10 2011 004 596 A1 a hydraulic tank of an industrial truck according to the preamble of claim 1 is known, which has support formations on both its underside and its top side for storing and fastening the tank in an industrial truck.

[0006] JP H 11 322 292 A describes an industrial truck with a support that has precisely one mount for accommodating a projection of a hydraulic tank. Spacers are also provided above and to the sides of the tank to secure the hydraulic tank.

[0007] Based on this, the object of the invention is to provide an industrial truck in which the hydraulic fluid tank is attached in a particularly simple yet safe manner.

[0008] This object is achieved by the industrial truck having the features of claim 1. Advantageous embodiments are specified in the subclaims.

[0009] The industrial truck has a carrier and a hydraulic fluid tank, whereby the hydraulic fluid tank has several feet and the carrier has several receptacles into which one of the feet is inserted.

[0010] The support feet can be located on the underside of the hydraulic fluid tank. They can protrude downward from a base surface of the hydraulic fluid tank. There can be at least three support feet, but also four or more. Each support foot can be assigned a correspondingly arranged support receptacle. The receptacles each have a free space, for example, in the form of a recess or a hole, which accommodates one of the support feet or a part of it.

[0011] To install the hydraulic fluid tank, it is sufficient to position the hydraulic fluid tank with its feet in a designated space on the industrial truck and insert the feet into the mounts. If the hydraulic fluid tank needs to be removed again, for example, for maintenance work, it can be easily lifted up and the feet are pulled out of the mounts. It has been found that the interaction of the feet with the mounts alone provides sufficient fastening of the hydraulic fluid tank. The positive fit between each foot and the corresponding mount reliably prevents the hydraulic fluid tank from slipping sideways. Additional vertical fastening of the hydraulic fluid tank has proven unnecessary.Even during strong acceleration or during impacts, such as those that may occur when driving over a threshold, the hydraulic fluid tank remains in its installed position.

[0012] In addition to the particular simplicity of the attachment in terms of design and with regard to installation or removal, the interaction of the feet with the mounts enables particularly precise positioning of the hydraulic fluid tank in the intended installation position. This helps ensure that elements formed on or connected to the hydraulic fluid tank, such as a filler neck for filling the hydraulic fluid tank, are also precisely positioned relative to the support. This is advantageous when these elements interact with other components of the industrial truck, such as an opening in a cover provided for the filler neck, the position of which is fixed relative to the support. The reason for the improved positioning accuracy is that the arrangement of the hydraulic fluid tank is independent of separately mounted spacers or clamps / brackets.Unlike these known fastening solutions, the installation of the hydraulic fluid tank does not result in any deformation of the hydraulic fluid tank, which can counteract the precise arrangement of a filler neck, for example.

[0013] In one embodiment, the hydraulic fluid tank is made of plastic and is manufactured using an injection molding or rotational sintering process. In a rotational sintering process, which is also referred to as a rotational melting process, plastic granules are melted in a counter-mold, and the counter-mold is rotated, usually around different axes of rotation, until the plastic material solidifies after cooling. Both manufacturing processes enable cost-effective production of the hydraulic fluid tank. However, there are limitations, particularly with regard to the possible shapes and wall thicknesses. For example, it is not easily possible to produce sections of the wall with an increased wall thickness using the rotational sintering process. This results in limitations with regard to the dimensional stability of the hydraulic fluid tank, which can make fastening with a clamp, for example, more difficult.However, these limitations are not relevant for the fastening by means of stands provided for in the invention.

[0014] In one embodiment, the receptacles in a horizontal section plane are completely filled by the support feet. This prevents the support foot from slipping sideways relative to the receptacle in the horizontal direction. This creates a positive connection that acts in all directions in the horizontal plane. Overall, the hydraulic fluid tank is particularly well secured. The receptacles and / or the support feet can, in principle, have any shape in the horizontal section plane, for example, square or rectangular. A circular cross-section is particularly advantageous.

[0015] In one embodiment, the mounts and / or feet are cylindrical. In particular, they can be circular cylindrical, for example. A conical design is also possible.

[0016] In the invention, the support feet protrude downward from a bottom surface of the hydraulic fluid tank, with the bottom surface being spaced from the support at all times. Optionally, all other surfaces, particularly the side surfaces, of the hydraulic fluid tank can also maintain a distance from the adjacent components of the industrial truck. This prevents damage to these surfaces, which could otherwise occur, for example, during vibrations if one of the surfaces rubs against a weld bead of a neighboring sheet metal.

[0017] In one embodiment, recesses are formed in a base surface of the hydraulic fluid tank, into which the support feet are inserted. This allows the support feet to be particularly easily attached to the hydraulic fluid tank by simply inserting them into the recesses. The dimensions of the recesses can be matched to the support feet so that the support feet are securely fixed after being pressed into the recesses. Suitable recesses, for example, circular-cylindrical depressions, can be easily produced by appropriately shaping the wall of the hydraulic fluid tank, in particular using the manufacturing processes already mentioned. Increasing the wall thickness is not necessarily required for this purpose.

[0018] In one embodiment, threaded inserts are arranged in the base of the hydraulic fluid tank, to which the support feet are screwed. For example, metal threaded inserts can be used, which are integrated into the wall of the hydraulic fluid tank during its manufacture. It is also possible to press the threaded inserts into suitable recesses or to glue them into them. The support feet can be manufactured as a single piece with an external thread or provided with a separate threaded bolt that is screwed into the threaded insert to secure the support foot.

[0019] In one embodiment, the feet are made of an elastic material. This elastic material allows for deformation of the feet. This allows for easy insertion of the hydraulic fluid tank with all feet into the corresponding receptacles, even with manufacturing tolerances. Furthermore, with appropriate fitting of the feet into the receptacles, additional frictional engagement can be achieved. Finally, sufficient elasticity of the feet allows for vibration isolation of the hydraulic fluid tank. A particularly suitable elastic material for the feet is nitrile rubber, also known as NBR for nitrile butadiene rubber (Acrylonitrile butadiene rubber).

[0020] In one embodiment, the support feet are manufactured as a single piece with the hydraulic fluid tank. In this case, they are made of the same material as the hydraulic fluid tank, in particular a plastic material. For example, corresponding support feet can easily be molded onto the hydraulic fluid tank during manufacture using one of the previously explained processes.

[0021] In one embodiment, a downward-facing bulge with a drain hose is arranged on the underside of the hydraulic fluid tank. The bulge is arranged laterally between the support feet and below a level in which the support feet are located. This ensures a secure stand for the hydraulic fluid tank with an optimally positioned extraction point at a lowest point, approximately in the center of the hydraulic fluid tank. In particular, access to the extraction point is not restricted by the support.

[0022] In one embodiment, the support is part of a vehicle base frame. In principle, the support can be any supporting structure for attaching the hydraulic fluid tank, for example, an intermediate floor or a profile support bolted or welded to the vehicle base frame. The support can also be formed from several elements that are connected to one another and / or attached to another supporting structure of the industrial truck. A particularly simple design results if the support is part of a vehicle base frame, meaning no separate support is required for the hydraulic fluid tank. In particular, the support can be a vehicle base frame component made of cast iron.

[0023] The invention is explained in more detail below with reference to the figures. They show: Fig. 1 an industrial truck in a perspective view, Fig. 2 a carrier of the industrial truck from Figure 1with built-in hydraulic fluid tank in a perspective view, Fig. 3 the carrier from Figure 2 in another perspective view, Fig. 4 a perspective view of a lower part of the hydraulic fluid tank from Figure 2 , Fig. 5the hydraulic fluid tank Figure 2 in a sectional view.

[0024] The industrial truck from Fig. 1 is a reach truck with two support arms 10, each with a load wheel 12 at its front end. Between the two support arms 10 is a movable lifting frame 14 with a load fork 16. The reach truck also has a driver's cab 18, in which the driver's seat 20 is located. A steerable drive wheel 22 can be seen on the underside of the reach truck. The base frame of the reach truck comprises a support 24, which is made of cast iron and also forms a counterweight. Fig. 1The concealed hydraulic fluid tank 26 is located approximately below the driver's seat 20.

[0025] The arrangement of the hydraulic fluid tank 26 on the carrier 24 is shown in Figure 2 shown. The hydraulic fluid tank 26 has a filling opening with a screw cap 28 on its top. A return line 30 also opens into the hydraulic fluid tank 26 on the top of the hydraulic fluid tank 26.

[0026] Other components of the reach truck are also attached to the carrier 24. These include a hydraulic motor 32, a traction drive motor 34 and a steering motor 36. All three motors are electric motors. Figure 2 an electronic control 38 of the reach truck can be seen, which is also attached to the carrier 24.

[0027] In Figure 3The support 24 is shown without the components attached to it. There, one can see four receptacles 40 formed on the support, into which the support feet 42 (see Figure 4 ) of the hydraulic fluid tank 26. In the example, the receptacles 40 are circular-cylindrical recesses that were produced during the manufacture of the support 24 by casting. Alternatively, corresponding receptacles 40 can also be created, for example, by milling or drilling. The four receptacles 40 lie in a horizontally arranged plane. Three of the receptacles 40 are formed in a web 44 running around an outer edge of the support 24, and a fourth of the receptacles 40 is located at a distance from the web 44 on a separate bulge 46 of the support 24. A free space 48 is located between the four receptacles 40 and below the plane in which the receptacles 40 are arranged.

[0028] Figure 4shows a perspective view of a lower portion of the hydraulic fluid tank 26. A bottom surface 50 is formed on the underside of the hydraulic fluid tank 26, from which the four support feet 42 protrude downward. The support feet 42 are circular cylindrical and made of nitrile rubber.

[0029] Between the feet 42, the hydraulic fluid tank 26 has a downward-facing, box-shaped recess 52 on its underside with a nozzle 54 for attaching a drain hose. This recess 52 with nozzle 54 and connected drain hose is accommodated in the free space 46 (see Figure 3 ). The feet 42 are dimensioned such that they essentially completely fill the receptacles 40 when inserted therein.

[0030] Figure 5shows the hydraulic fluid tank 26 in a vertical sectional plane passing through the screw cap 28 and two of the support feet 42. Also visible is the support 24 with two of the receptacles 40, into each of which one of the support feet 42 is inserted. Also clearly visible in Fig. 5 It can be seen that the floor surface 50 as well as the side surfaces of the hydraulic fluid tank 26 maintain a distance from the adjacent elements of the industrial truck, in particular from the carrier 24.

[0031] The support feet 42 are also inserted into recesses 56 in a base 58 of the hydraulic fluid tank 26 and are thus secured to the hydraulic fluid tank 26. The wall of the hydraulic fluid tank 26 has a substantially uniform thickness. List of reference symbols :

[0032] 10Wheel arm 12Load wheel 14Lift mast 16Load fork 18Driver's cab 20Driver's seat 22Drive wheel 24Carrier 26Hydraulic fluid tank 28Screw cap 30Return line 32Hydraulic motor 34Traction drive motor 36Steering motor 38Electronic control 40Receiver 42Stand 44Bridge 26Bump 48Free space 50Floor surface 52Bump 54Connector 56Recess 58Floor

Claims

1. An industrial truck having a base (24) and a hydraulic fluid tank (26), wherein the hydraulic fluid tank (26) comprises multiple feet (42), characterized in that the base (24) comprises multiple receiving portions (40) into each of which one of the feet (42) is inserted, wherein the feet (42) protrude downwards from a bottom surface (50) of the hydraulic fluid tank (26), the bottom surface (50) is arranged at all points at a distance from the base (24), and there is a form fit between each of the feet (42) and the associated receiving portion (40).

2. The industrial truck according to claim 1, characterized in that the hydraulic fluid tank (26) consists of plastics material and is produced in an injection molding or rotational sintering process.

3. The industrial truck according to claim 1 or 2, characterized in that the receiving portions (40) are completely filled by the feet (42) in a horizontal sectional plane.

4. The industrial truck according to one of claims 1 to 3, characterized in that the receiving portions (40) and / or the feet (42) are cylindrical.

5. The industrial truck according to one of claims 1 to 4, characterized in that recesses (56) into which the feet (42) are inserted are formed in a bottom surface (50) of the hydraulic fluid tank (26).

6. The industrial truck according to one of claims 1 to 5, characterized in that threaded inserts by means of which the feet (42) are screwed down are arranged in a bottom (58) of the hydraulic fluid tank (26).

7. The industrial truck according to one of claims 1 to 6, characterized in that the feet (42) consist of a resilient material.

8. The industrial truck according to one of claims 1 to 4, characterized in that the feet (42) are produced integrally with the hydraulic fluid tank (26).

9. The industrial truck according to one of claims 1 to 8, characterized in that a downward-pointing bulge (52) having a drainage hose is arranged on an underside of the hydraulic fluid tank (26), wherein the bulge (52) is arranged, in a lateral direction, between the feet (42) and below a plane in which the feet (42) are located.

10. The industrial truck according to one of claims 1 to 9, characterized in that the base (24) is part of a vehicle chassis.