Abstract:
Fixed connector part ( 10 ), adapted to constitute an end part of a hydraulic system of a work vehicle ( 1 ) and intended to be fixedly arranged on the work vehicle ( 1 ), the fixed connector part ( 10 ) comprising: at least two hydraulic couplings ( 14   a - d ); a first locking means ( 13, 16 ), which is intended to interact with a second locking means ( 23, 26 ) on a movable connector part ( 20 ), which constitutes an end part of a hydraulic system of a work equipment ( 2 ), wherein the first and second locking means are inter-connectable such that the hydraulic couplings of the fixed connector part ( 10 ) and the movable connector part ( 20 ), respectively, may be simultaneously interconnected through the interaction of the first and second locking means. Further each hydraulic coupling ( 14   a - d ) of the fixed connector part ( 10 ) comprises individual couplings, such that each hydraulic coupling ( 14   a - d ) of the fixed connector part ( 10 ) may be individually connected to a separate hydraulic coupling ( 24   a - d ). The invention also involves an arrangement including such a fixed connector part.

Description:
TECHNICAL AREA 
       [0001]    The present invention relates to a fixed connector part of a hydraulic system, and a hydraulic connection arrangement including such a fixed connector part. 
       BACKGROUND OF THE INVENTION 
       [0002]    There are several applications where hydraulic connectors are utilized for inter-connecting hydraulically controlled equipments with systems of pressurized hydraulic fluid comprising control means such as valves for directing the pressurized fluid to different parts of the equipment and/or different functions of the equipment. 
         [0003]    In many applications it is advantageous if the hydraulic connections are of a so called multi coupling type, with which it is possible to connect and disconnect the hydraulically controlled equipment from the source in one single operation. One such application is work vehicles for e.g. agricultural use, i.e. tractors, which utilize a number of different equipment such as digging aggregates, lifting aggregates, ploughs and the like. These are hydraulically operated via conduits and valve systems connected to a source of pressurized fluid, such as hydraulic pumps, which are driven by the engine of the work vehicle. Often, such an equipment is disconnected from the tractor when it is not to be used for a while, such that it may be replaced by another hydraulically controlled equipment. 
         [0004]    A few systems for facilitating the operation of coupling the hydraulically controlled equipment to the work vehicle have been developed. One is disclosed in EP 0 522 493, in which hydraulic conduits are attached to carrier plates, one carrier plate being attached in a fixed position on e.g. a work vehicle, and the other carrier plate being arranged to the attachable equipment. The carrier plates are arranged with leakage proof quick-acting couplings. For connecting the couplings, a handle is pivotally arranged on the fixedly attached carrier plate, which co-operates with a couple of clamping pins arranged on the other carrier plate. 
         [0005]    An obvious advantage of a multi coupling, such as the one described in EP 0 522 493 is of course that the exchange of equipments on the work vehicle may be easily and quickly performed. A drawback is however that once the work vehicle is supplied with such a carrier plate all equipment that are intended for use on that work vehicle, i.e. digging aggregates, lifting aggregates, ploughs etc., needs to be furnished with a corresponding carrier plate. This may infer heavy investment costs that are in some cases difficult to recover. Some of the equipments are only used once or twice a year, wherein such an investment is not worth wile. 
         [0006]    Another drawback with the solution presented in EP 0 522 493 is that when the carrier plates are disconnected from each other, the couplings are not protected and are thus exposed to harming elements of the environment, such as dirt, debris, snow, rain and ice. This could adversely affect the hydraulic system, leading to malfunction and breakdown with rather costly repairs as a result. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0007]    The aim of the present invention is to provide a fixed hydraulic connection, which is adaptable and easy to operate, but which does not infer the installation of costly hydraulic connections on all auxiliary equipments that are intended to be connected to the fixed hydraulic connection. 
         [0008]    This is achieved according to the present invention by the features of claim  1 . Preferable embodiments of the present invention are indicated in the dependent claims. 
         [0009]    According to a first aspect, the invention relates to a fixed connector part, adapted to constitute an end part of a hydraulic system of a work vehicle and intended to be fixedly arranged on the work vehicle, the fixed connector part comprising: at least two hydraulic couplings; and a first locking means, which is intended to interact with a second locking means on a movable connector part, which constitutes an end part of a hydraulic system of a work equipment, wherein the first and second locking means are inter-connectable such that the hydraulic couplings of the fixed connector part and the movable connector part, respectively, may be simultaneously interconnected through the interaction of the first and second locking means. Further, each hydraulic coupling of the fixed connector part comprises individual couplings, such that each hydraulic coupling of the fixed connector part may be individually connected to separate hydraulic couplings. 
         [0010]    An advantage of the present invention lies in the flexibility of the unit, residing in the fact that a work equipment may be used with and connected to the fixed connector part regardless of the type of coupling arranged on the work equipment. 
         [0011]    Further, according to a second aspect, the invention relates to a hydraulic connection arrangement including a fixed connector part as described above. 
         [0012]    The arrangement also comprises a movable connector part, which is adapted to be easily connected to the fixed connector part. Further, the arrangement preferably comprises a holding means for parking the movable connector part when it is detached from the fixed connector part, and a cover for protecting the fixed connector part when the movable connector part is not connected to it. The cover is preferably adapted to protect the holding means when the movable connector part is connected to the fixed connector part. 
         [0013]    Thus, the holding means and the cover provide a full protection for the connector parts. Both the fixed connector part and the movable connector part may be protected from the environment at all times. Additionally the holding means is also protected at all times. 
         [0014]    These and other aspects and advantages of the present invention will become apparent from the following detailed description of the invention and from the accompanying drawings. 
     
    
     
       SHORT DESCRIPTION OF THE DRAWINGS 
         [0015]    In the following detailed description of the invention, reference will be made to the accompanying drawings, of which: 
           [0016]      FIG. 1  shows a work vehicle provided with a fixed connector part according to the invention, wherein a work equipment with a movable connector part is connected to the work vehicle, 
           [0017]      FIG. 2  shows a detailed view of the fixed connector part of  FIG. 1 , 
           [0018]      FIG. 3  shows a work vehicle with a disconnected work equipment, 
           [0019]      FIG. 4  shows a detailed view of the fixed connector part of the hydraulic connection of  FIG. 3  provided with a cover, 
           [0020]      FIG. 5  shows a detailed view of the movable connector part of the hydraulic connection of  FIG. 3 , parked in a holding means, 
           [0021]      FIG. 6  shows the fixed connector part of the hydraulic connection and three sets of connectable fittings, 
           [0022]      FIG. 7  shows the holding means and three sets of connectable fittings, 
           [0023]      FIG. 8  shows the fixed connector part in detail, 
           [0024]      FIG. 9  shows the holding means in detail, 
           [0025]      FIG. 10  shows a view of the movable connector part connected to the fixed connector part, 
           [0026]      FIG. 11  shows a view of the movable connector part connected to a fixed connector part, which is integrated with a valve block, 
           [0027]      FIG. 12  shows the movable connector part parked in the holding means, 
           [0028]      FIG. 13  shows 4 individual hydraulic couplings parked in the holding means, 
           [0029]      FIG. 14  shows 2 individual hydraulic couplings parked in the holding means, 
           [0030]      FIG. 15  shows a cover arranged on the holding means, 
           [0031]      FIG. 16  shows an electrical connection according to a second preferred embodiment, 
           [0032]      FIG. 17  shows a movable connector part according to a second preferred embodiment, 
           [0033]      FIG. 18  shows a fixed connector part according to a second preferred embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]      FIG. 1  shows a schematic view of a work vehicle  1 , i.e. a tractor, provided with a conventional hydraulic system comprising a hydraulic pump, a tank with hydraulic fluid and a number of conduits, connections and valves. The hydraulic system comprises a fixed connector part  10  according to the invention, which is adapted to be connected to a movable connector part  20  of a hydraulic system on a work equipment  2  to be used on the work vehicle  1 . 
         [0035]    Often, a work vehicle  1  is used for a number of different work tasks involving different work equipments  2 . In the figures, the work equipment  2  is exemplified by a front loader unit, which is releasably attached to the work vehicle  1 . In addition to the movable connector part  20 , the front loader is provided with a hydraulic system comprising connections, conduits and pistons for lifting the loader and tilting the bucket. Other types of usable work equipments include digging aggregates, lifting aggregates, ploughs and the like. Generally, all these different types of equipments are adapted to be releasably attached to the work vehicle  1 . Hence, the hydraulic connection unit of the work equipments  2 , i.e. the movable connector part  20 , must be adapted to be connected to/disconnected from the fixed connector part  10  of the hydraulic system on the work vehicle  1 . Additionally, different tools may be connected to the work equipment  2 . The tools generally also include hydraulic systems, which systems need to be connected to the hydraulic system of the work vehicle, via the hydraulic system of the work equipment  2 . These connections might or might not be of the same type as the connections between the work equipment  2  and the work vehicle  1 . For the sake of simplicity, only the connection between the work equipment  2  and the work vehicle  1  is described in this application. The invention may however also be used at the connection between the work equipment  2  and the tool. 
         [0036]      FIGS. 1-2  shows the work vehicle  1  when the work equipment  2  is arranged on it. In this state, the movable connector part  20  is connected to the fixed connector part  10 , and a cover  40  is arranged to protect a holding means  30 , which is arranged on the work equipment  2 . 
         [0037]    In  FIGS. 3-5 , the work equipment  2  is disconnected from the work vehicle  1 . In this state the movable connector part  20  is parked in the holding means  30 , and the cover  40  is instead arranged on the fixed connector part  10  in order to protect it. 
         [0038]    According to the present invention a multi coupling arrangement is provided between the hydraulic system of the work vehicle and the hydraulic system of the front loader. As indicated above the multi coupling arrangement comprises two parts, wherein one fixed connector part  10  is connected to the hydraulic conduits of the work vehicle  1 , and one movable connector part  20  is arranged on the work equipment  2 . The fixed connector part  10  is preferably fixedly attached to the work vehicle on a suitable location where it does not interfere with the function of the work vehicle and/or the attached work equipment  2 . The fixed connector part  10  of the multi coupling comprises a housing on which a number of conduit attachments are arranged. 
         [0039]    Depending on the type of work vehicle  1  and its hydraulic system, the fixed connector part  10  of the present invention may be integrated in a valve block  3 . However, on some work vehicles the valve block  3  is included in the hydraulic system of the work vehicle. In such a case the fixed connector part  10  and the valve block  3  may be configured as separate parts that are interconnected by hydraulic conduits. 
         [0040]    In the shown embodiment the fixed connector part  10  is integrated in the valve block  3 . An inlet conduit  11   a  for pressurised hydraulic fluid from the pump of the hydraulic system of the work vehicle  1  and a return conduit  11   b  for returning hydraulic fluid to the tank of the hydraulic system is connected to the valve block  3 . Further, an electric cable  12  is connected to the valve block  3  for furnishing electricity to the work equipment. Often, wires (not shown) are connected to the valve block for allowing the operator to control the fluid in the valve block  3  and thus the functions of the work equipment  2 . Generally the valve block  3  includes 2 spool valves, which are regulated by the wires and which control the passages of the hydraulic fluid. The control of the valves may also be electrically handled, wherein no wires are connected to the valve block  3 . 
         [0041]    As is best shown in  FIG. 6  and  FIG. 8 , the fixed connector part  10 , is provided with a central bar  13  comprising engagement pegs  16  for enabling coupling to the fixed connector part  10 . Further, it comprises four conduit couplings  14   a - d  for the hydraulic lines, and an electric connection  15 , which in the embodiment shown in  FIGS. 1-15  is provided on the top of the central bar  13 . 
         [0042]    A movable connector part  20  in accordance with the invention may be connected to the fixed connector part  10  in one single operation. The movable connector part  20  comprises a number of conduit openings having a configuration and design to mate with the conduit couplings  14   a - d  of the fixed connector part  10 , such that each conduit opening is connected in a fluid tight manner to the corresponding conduit coupling  14   a - d  of the fixed connector part for providing fluid tight passages for the hydraulic fluid. Further the movable connector part  20  comprises an electric connection mating with the electric connection  15  of the fixed connector part  10 . Both the fixed connector part  10  and the movable connector part  20  are configured such that any dripping of fluid is avoided in both the connected and the disconnected state. The fluid connections in them selves are well known to he skilled person and are therefore not described in detail in this application. In the shown embodiment, the actual connection of the movable connector part  20  to the fixed connector part  10  is enabled at the central bar  13 , as is described below. 
         [0043]    The movable connector part  20  is provided with a central bore (not shown). Inside the bore, a sleeve (not shown) is arranged rotary around its own longitudinal axis. The sleeve constitutes the female part of the coupling and is designed to mate with the central bar  13  of the fixed connector part  10 , the central bar  13  constituting the male part of the coupling. A lever  23  (see e.g.  FIG. 6 ) is attached to the sleeve for rotating the same and protrudes through an opening  27  in the housing of the movable connector part  20 . The sleeve of the movable connector part  20  is provided with curved grooves (not shown) on its inner surface, and when the lever  23  is turned to rotate the sleeve, the grooves on the inner surface of the sleeve interact with the engagement pegs  16  on the bar  13 , whereby the parts are forced towards each other and locked to each other. A blocking pin  26  is arranged to keep the lever in the closed position when the movable connector part  20  is attached to the fixed connector part  10 . The coupling of the movable connector part  20  to the fixed connector part  10  may be designed in many different manners. For instance each of the conduit couplings  14   a - d  may be provided with locking means mating with locking means on the movable connector part. Other types of couplings are also known in the art, i.e. from EP 0 522 493, as cited above. Hence the coupling between the fixed connector part  10  and the movable connector part  20  is not restricted to the shown embodiment. 
         [0044]    An important feature of the fixed connector part  10  is that it is also conceivable to connect conventional individual hydraulic couplings to it. Thus, it is not necessary to provide all work equipments  2  that are to be connected to a work vehicle  1  provided with a fixed connector part  10  according to the invention with a movable connector part  20 . 
         [0045]    From  FIGS. 6 and 8 , it is apparent that all individual hydraulic connections  14   a - d  are configured as conventional hydraulic quick couplings, which may be directly connected and locked to individual hydraulic couplings of a work equipment without use of a multi coupling. Preferably the quick coupling are of a standard type. e.g. as certified under ISO 16028. 
         [0046]    Thus, as is shown in  FIGS. 6 ,  13  and  14 , individual hoses  21   a - d  and optionally an electric cable  22  may be individually coupled to the fixed connector part  10 . In the shown embodiment the hoses  21   a - d  are each provided with individual female parts  24   a - d  of a hydraulic quick coupling mating with the corresponding male parts  14   a - d  of the fixed connector part  10 . The electric cable  22  is coupled via an electric connector housing  25 , adapted to mate with the bar  13  of the fixed connector part  10 , and thus comprising a bore for receiving the bar  13  and tracks  18  for receiving the engagement pegs  16  of the bar. The tracks  18  are configured as key holes, i.e. with a circular top which fits tightly around the engagement pegs  16 , and with narrow part separating the circular part from the lower linear part of the track  18 . The narrow part locks the connector housing  25  to the central bar  13 . 
         [0047]    In certain applications only two hydraulic couplings are needed, e.g. when the work equipment comprises only one hydraulic cylinder. Such an arrangement is shown in  FIG. 14 , where two of the connections are left uncoupled. In  FIG. 14 , the couplings  24   a  and  24   b  are coupled to openings  34   b  and  34   c  of a holding means  30 . They may of course, in use, be connected in a corresponding manner to a fixed connector part  10  of a work vehicle  1 . 
         [0048]    As mentioned above and according to another aspect of the invention a holding means  30  or a “parking slot” is arranged on the work equipment  2  on a suitable location where it does not interfere with the function of the work equipment. The holding means  30  is designed such that it mates with the movable connector part  20 . Thus, it resembles the fixed connector part  10  and comprises an upper surface  32  arranged to correspond to and co-act with the connection surface of the movable connector part  20 , in order to protect the connection surface of the movable connector part when attached to the holding means  30 . The holding means  30  is provided with a central bar  33  corresponding to the bar  13  of the fixed hydraulic connection part  10 , with or without engagement pegs (corresponding to the engagement pegs  16  of the fixed connector part  10 ). In the shown embodiment the bar  33  is not provided with engagement pegs. The holding means  30  is instead provided with a rim  31 , inside which the movable connector part  20  fits tightly, such that it is efficiently held at place. Further, the holding means  30  is adapted to receiving conventional hydraulic couplings. Openings  34   a - d  are arranged in the holding means  30 , which are dimensioned to house individual couplings  24   a - d , see e.g.  FIG. 13 . Consequently, a holding means  30  is preferably arranged on all work equipments  2  that are to be used on the work vehicle  1 , regardless of the type of connection the hydraulic system of the work equipment  2  is provided with. 
         [0049]    When the work equipment  2  is not to be used any more, the movable connector part  20  is disconnected from the fixed connector part  10  on the work vehicle and inserted into the holding means  30  in which it fits tightly and remains fixed. The movable connector part  20  is thus kept out of the way and is at the same time protected from the environment, such that dirt, debris, ice, snow etc. is kept away from its connection surface. Conventionally the connection part of the work equipments have been left exposed to the environment, which of course may lead to all kinds of problems, including total failure of the connector part due to impact with neighbouring objects, and heavy soiling of both the connector part and the environment due to spillage of hydraulic fluid. 
         [0050]    If the work equipment  2  is furnished with individual quick couplings  24   a - d  instead of a movable connector part  20 , these may be individually housed in the openings of the holding means  30 , and the electric connector housing  25  may be arranged on the central bar  13 . 
         [0051]    A second protecting means, in form of a cover  40 , is provided in accordance with the present invention on the one hand for protecting the fixed connector part  10  when the movable connector part  20  is not connected to it, and on the other for protecting the holding means  30  when the movable connector part  20  is connected to the fixed connector part  10 . The cover  40  is arranged as a lid with a lower surface that corresponds to the lower surface of the movable connector part  20 , such that it fits the upper surface of the fixed connector part  10  and the holding means  30 . The cover  40  may further be arranged with a central sleeve which protrudes through an opening in the cover, and is connected to a knob  41  for turning the sleeve around its longitudinal axis. The sleeve may have the same configuration as the sleeve of the movable connector part  20 , which enables the sleeve to be attached to the central bar  13  of the fixed connector part  10  in order to protect the hydraulic connections of the fixed connector part  10  when it is not in use. On the other hand, when the hydraulic system of the equipment is connected to the hydraulic system of the work vehicle, the cover is attached to the holding means  30  in order to protect the holding means  30  from dirt and debris. Thus, the holding means  30  and the cover  40  provides a full protection of the hydraulic connection parts of the present invention both during use and when parked. 
         [0052]    A second preferred embodiment of the invention is shown in  FIGS. 16-18 . In  FIG. 16 , an individual electrical connection part  15 ′ is shown. An advantage of the second preferred embodiment of the invention is that the electrical connection part  15 ′ is of a conventional type, which is readily available on the market, such that spare parts may be easily available. 
         [0053]    Also, as is shown in  FIG. 17 , the movable connector part  20  may be provided with a corresponding electrical connection  15 ′ that is fixed to its outer part. Accordingly, the fixed connector part  10  (as is shown in  FIG. 18 ) is provided with a mating electrical connector part  15 ″. Preferably, the fixed connector part  10  is provided with the male part of the connector, such that no upward open recess is formed on the fixed connector part  10 , whereby the possibility of collecting dust or similar is minimised. 
         [0054]    The fixed connector part  10  may thus be connected either to individual hydraulic couplings and an individual electrical connection  15 ′, or to a movable connector part  20 , which may or may not involve an electrical connection  15 ′. The electrical connection parts  15 ′ and  15 ″ may include snap connections  51   a  and  51   b , such that an individual electrical connection  15 ′ may be releasably connected to the electrical connection  15 ″ of the fixed connector part. An electrical connection  15 ′ that is integrated onto a movable connector part  10  is preferably not provided with such a snap in connection. Instead, the movable connector part  20  is rigidly connected to the fixed connector part  10  by means of the central bar  13 ′ with the engagement pegs  16  on the fixed connector part  10 , which interact with curved grooves on the inner surface of a sleeve (not shown) in the movable connector part  20 . As described above, the lever  23  is connected to the sleeve, such that the movable connector part  20  may be locked to the fixed connector part  10  by rotating the lever  23 . This overall connection simultaneously secures the four hydraulic conduit couplings  14   a - d  and the electric connection parts  15 ′ to their corresponding connection. 
         [0055]    When the second preferred embodiment of the invention is implemented, a holding means (not shown) that mates the movable connector part  20  according to the second embodiment shall be used, as well as a cover (not shown) that is adapted to mate with the fixed connector part  10  of the second embodiment and the corresponding holding means. 
         [0056]    As can be readily understood from the above the present invention may be designed in many ways without departing from the scope of protection as defined by the claims. It is thereby to be understood that the embodiments described above and shown in the drawings are to be regarded as non-limiting examples.