JP6641322B2 - Vehicle maintenance lift - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle maintenance lift for lifting a vehicle from a floor of a maintenance yard to perform inspection and maintenance of an engine, a brake, and the like, and replace parts.

  As a conventional vehicle maintenance lift, for example, as described in Patent Literature 1, columns are erected on the left and right sides of the floor of a maintenance yard, and elevating bodies are provided on the left and right columns so as to be able to control the vertical movement, and A telescopic lift arm is pivotally attached to the front and rear part of the body, and a bracket is attached to each end of each lift arm, and each bracket is applied to a corresponding lift point on the lower surface of the vehicle. There is known an apparatus which raises the vehicle from the floor of a maintenance yard by synchronously raising left and right elevating bodies.

  In a conventional vehicle maintenance lift, when a vehicle is lifted up, the vehicle is lifted up in a state in which the weight balance of the vehicle supported by each lift arm is largely disturbed without a worker noticing. Even if the vehicle is lifted up without dropping from the arm or the weight balance of the vehicle has not been lost, the weight balance has been lost due to heavy maintenance such as replacing parts of the engine etc. during inspection and maintenance, and the vehicle has been lifted by each lift arm. There is a possibility that the device may fall from the ground, and an abnormality detection device for avoiding such an abnormal situation has been proposed.

  The abnormality detection device proposed in the conventional vehicle maintenance lift is provided with a load sensor that hits each lift point of the vehicle on a receiving member of each lift arm, and hits each lift point when the vehicle is lifted up by each lift arm. When the difference between the detected loads (lift loads acting on the lift arms) from the load sensors provided on the receiving bracket is larger than a specified value, the lift load of the vehicle supported by each lift arm is abnormal. It is determined that the lift state is in an abnormal state and the lift state is in an abnormal state, and the abnormality is notified by alarm means.

JP 2004-284714 A

  However, according to the verification experiment of the present inventor, according to the conventional abnormality detection device for a vehicle maintenance lift, even if the lift state of the vehicle by each lift arm is not an abnormal state in actual use, each of the lift arm Frequently, it is determined that the lift load of the vehicle is in an abnormally unbalanced state and the lift state is in an abnormal state, and the worker stops lifting the vehicle each time and temporarily removes the vehicle from the floor of the maintenance yard. Then, it is necessary to perform an adjustment work to correctly apply the metal fittings of each lift arm to each lift point of the vehicle, lift up the vehicle again, and repeat the work of judging the abnormality of the lift state.

  The adjustment work described above, in which the fittings of each lift arm are correctly applied to each lift point of the vehicle, is performed by looking into the lower surface of the vehicle, and the fittings of each lift arm are positioned at each lift point on the lower surface of the vehicle. Rotate and extend and retract each lift arm so that they match, or move up and down so that the metal fittings of each lift arm touch the corresponding lift points without any gaps, and delicately set the height of the metal fittings with respect to the lift arm. It requires adjustment and the like, which is difficult even for a skilled person, and significantly reduces the work efficiency of vehicle maintenance.

  An object of the present invention is to provide a vehicle maintenance lift that rationally determines whether or not the lift load of a vehicle supported by each lift arm is in an abnormally unbalanced state and the lift state is in an abnormal state. The purpose is to improve the maintenance work efficiency.

  The invention according to claim 1 performs a lift operation of supporting a vehicle by a vehicle support portion provided on each of a plurality of lift arms that move up and down in synchronization, and a load sensor is provided on each of the vehicle support portions of each lift arm, Control means is provided for determining that the lift state of the vehicle by each lift arm is in an abnormal state based on that the imbalance between the detected loads of the load sensors has reached a certain abnormal imbalance or more. The vehicle maintenance lift according to claim 1, wherein the control unit is configured to control the vehicle support of all lift arms from a point in time when a load sensor of at least one of the plurality of lift arms first detects a lift load. The range of the height of each lift arm is assumed to be the dead zone height until it is assumed that the section will support the vehicle. It is presumed that the vehicle support portions of all lift arms have supported the vehicle when the vehicle is at the position exceeding the height of the sensing zone, and whether the lift state of the vehicle by each lift arm is in the abnormal state described above. It is determined whether or not it is.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the control unit determines that the lift state of the vehicle is in the abnormal state during a lift operation of the vehicle by each lift arm, The lifting of the arm is stopped.

  According to a third aspect of the present invention, in the first aspect of the present invention, furthermore, the control means is arranged such that the lift position of each lift arm is at a position exceeding the height of the dead zone, and that the lift arms are stopped during the lift. Further, when it is determined that the lift state of the vehicle by each lift arm is in the abnormal state, each lift arm can be lowered only by a special operation.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the control means sets the dead zone height of each lift arm to a set value selected from a range of 30 mm to 60 mm. It was made.

によって求めるとともに、前記異常非均衡度を90％以下、より好適には60％以下の範囲内から選ばれた設定値とし、２個以上の上記非均衡度がその設定値以上に達したことに基づいて、各リフトアームによる車両のリフト状態が異常事態にあるものと判定するようにしたものである。 The invention according to claim 5 is the invention according to any one of claims 1 to 4, further comprising four front, rear, left, and right lift arms, and the control means is provided in each of the vehicle support portions of each lift arm. When the detected loads of the detected load sensors are A to D, the unbalance degrees Fab, Fac, Fbd, and Fcd between the respective detected loads A to D are represented by:

And the abnormal imbalance is set to a set value selected from a range of 90% or less, more preferably 60% or less, and the two or more imbalances reach the set value or more. Based on this, it is determined that the lift state of the vehicle by each lift arm is in an abnormal state.

(Claim 1)
(a) It is assumed that from the time when the load sensor of at least one of the plurality of lift arms first detects the lift load, the vehicle supports of all the lift arms will support the vehicle. When the lift height of each lift arm is the dead zone height, and when the lift position of each lift arm exceeds the dead zone height, the lift support stage in which the vehicle supports of all lift arms support the vehicle Is determined, and it is determined whether or not the lift state of the vehicle by each lift arm is abnormal.

  Thus, when the lift position of each lift arm does not reach the dead zone height, the control means is in the aforementioned lift transition stage with respect to the vehicle, and the imbalance between the detected loads of the load sensors is detected. It is determined that the abnormal values tend to show abnormal values exceeding a certain abnormal imbalance degree, and no unreasonable abnormal judgment based on such abnormal values in the lift transition stage is performed.

  Then, the control means estimates that when the lift position of each lift arm exceeds the dead zone height, the vehicle support portions of all the lift arms have reached the lift steady stage where they correspond to the corresponding lift points of the vehicle. It is calculated whether the unbalance of the load detected by each load sensor has reached or exceeded a certain abnormal unbalance, and based on the calculation result, the lift load of the vehicle supported by each lift arm is abnormal. It is reasonably determined whether or not the lift state is in an unbalanced state and the lift state is abnormal. As a result, even if the lift state of the vehicle by each lift arm is not abnormal in actual use, the lift load of the vehicle by each lift arm is in an abnormally unbalanced state and the lift state is abnormal. Is reduced rationally, and the vehicle maintenance work efficiency is improved without repeatedly repeating the lift-up / down of the vehicle every time the abnormality is determined and repeatedly performing the abnormality determination work.

(Claim 2)
(b) According to the above (a), when the control means determines that the lift state of the vehicle is in an abnormal state during the lift operation of the vehicle by each lift arm, the control means stops lifting and lowering of each lift arm.

(Claim 3)
(c) The control means sets the lift state of the vehicle by each lift arm according to the above (a) while the lift position of each lift arm is at a position exceeding the dead zone height, and while lifting of each lift arm is stopped. When it is determined that there is an abnormal situation, each lift arm can be lowered only by a special operation.

(Claim 4)
(d) The control means sets the dead zone height of the lift position of each lift arm to a set value selected from the range of 30 mm to 60 mm. Thereby, the control means rationally determines the abnormal imbalance state of the lifted-up vehicle.

(Claim 5)
(e) When the vehicle maintenance lift has four front, rear, left, and right lift arms, the control means controls the imbalance among the detected loads A to D of the load sensors provided on the respective vehicle support portions of each lift arm. When two or more Fab to Fcd of the degrees Fab to Fcd reach 90% or less, and more preferably 60% or less, and reach an abnormal imbalance degree set or more, each lift arm It is determined that the lift state of the vehicle is in an abnormal state. Thus, the control means rationally determines an abnormal imbalance state in which the vehicle shakes when the lifted-up vehicle is pushed by hand.

FIG. 1 is a schematic diagram showing a vehicle maintenance lift. FIG. 2 is a schematic diagram showing a lift arm. 3A and 3B show a vehicle support portion of the lift arm, in which FIG. 3A is a cross-sectional view showing a state in which the rubber receiving portion is lowered, FIG. 3B is a cross-sectional view showing a state in which the rubber receiving portion is raised, and FIG. () Is an exploded sectional view. FIG. 4 is a control system diagram of the vehicle maintenance lift. FIG. 5 is a schematic diagram showing a lift point of the vehicle.

  The vehicle maintenance lift 10 is, for example, a two-post type lift (other types of lifts are also possible) as shown in FIG. 1, is installed on a floor 11 of a maintenance yard, and has two right and left columns 12, 12. It stands on both sides of the lift work area 13 on the floor surface 11 with a predetermined interval. Both columns 12, 12 form a portal connected by a connecting beam.

  The lift 10 is equipped with left and right elevating bodies 15L and 15R that can be raised and lowered synchronously with each of the columns 12, respectively, and provided with left and right lift arms 16A and 16B at the front of the elevating bodies 15L and 15R. Left and right lift arms 16C, 16D are provided at the rear of the bodies 15L, 15R. The lift arms 16A to 16D can move up and down in synchronization with the lifts 15L and 15R, and are supported by the lifts 15L and 15R so as to be pivotable in a horizontal plane, and can expand and contract in their axial directions.

  As shown in FIG. 2, each of the lift arms 16A to 16D has a vehicle support portion 20A to 20D at a distal end thereof. Each of the lift arms 16A to 16D aligns each of the vehicle supports 20A to 20D with the corresponding lift point 2A to 2D (FIG. 5) on the lower surface of the vehicle 1 by turning and expanding and contracting in a horizontal plane, and The vehicle 1 is lifted up in synchronization with the lifting / lowering bodies 15L and 15R, and the metal support 23 of each of the vehicle support portions 20A to 20D is applied to each of the lift points 2A to 2D to support the vehicle 1. From the floor 11 of the maintenance yard.

  As shown in FIG. 3, each of the vehicle support portions 20A to 20D includes an outer bush 21, an inner bush 22, and a metal fitting 23, and also includes a load sensor 24 (24A to 24D). The outer bush 21 is fitted into a fitting hole 16H provided at the tip of each of the lift arms 16A to 16D, and the upper flange portion 21F is supported on the upper surface around the fitting hole 16H of each of the lift arms 16A to 16D. Thus, the lift arms 16A to 16D are fixed by the bush fixing pins 25. The outer bush 21 has a fitting hole 21H into which the inner bush 22 is freely movable up and down, and a load sensor 24 is fixedly arranged at the bottom of the fitting hole 21H. The inner bush 22 is fitted into the fitting hole 21H of the outer bush 21 so as to be vertically movable, is mounted on a load sensor 24 disposed at the bottom of the outer bush 21, and the receiving member 23 is fitted. A fitting hole 22H is provided. The metal fitting 23 is fitted to the fitting hole 22H of the inner bush 22, and is fixed to the outer bush 21 with the upper flange portion 23F supported on the upper surface around the fitting hole 22H of the inner bush 22. The tip protruding portion of the fixing pin 26 is loosely inserted into the side surface hole 23 </ b> H of the metal receiving member 23 through a certain play, and as a result, the outer bush 21 is held so as to be relatively movable in the vertical direction. The inner bush 22 is sandwiched between the load sensor 24 and the metal fitting 23 arranged at the bottom of the outer bush 21. The metal fitting 23 is mounted on the load sensor 24 via the inner bush 22. The metal fitting 23 is provided with the metal rubber part 23A by screwing the screw part 23B of the metal rubber part 23A in a vertically operable manner, and the position of the vehicle 1 to each of the corresponding lift points 2A to 2D. At the time of alignment, the set height of the rubber receiving portion 23A with respect to each of the lift arms 16A to 16D is adjusted, and the rubber receiving portion 23A is applied to each of the corresponding lift points 2A to 2D of the vehicle 1 without any gap, or a small gap is formed. The receiving rubber portion 23A can be moved up and down so as to intervene. When the metal fittings 23 of the vehicle support portions 20A to 20D hit the lift points 2A to 2D and lift up the vehicle 1, the lift loads A to D of the vehicle 1 acting on the metal fittings 23 become the load sensors 24 ( 24A to 24D) (FIG. 5).

  The lift 10 causes the control unit 30 shown in FIG. 4 to raise and lower the lifters 15L and 15R and the lift arms 16A to 16D.

  The control unit 30 has, as the operation unit 40, a normal operation switch 41 including a push button type up button 41U and a down button 41D.

  When the on operation of the ascending button 41U of the normal operation switch 41 by the worker is transmitted to the control means 30, the controlling means 30 sends an ascending operation signal resulting from the on operation of the ascending button 41U to the on state of the on operation of the ascending button 41U. It outputs for the same time length as the continuation time, and drives the hydraulic pump of the hydraulic drive unit of the ascending drive unit 51U, for example. Thereby, the hydraulic pump of the hydraulic unit feeds oil to the supply pipeline of each hydraulic cylinder corresponding to each of the lifting and lowering bodies 15L, 15R to extend those hydraulic cylinders, and each of the lifting and lowering bodies 15L, 15R and each of the lift arms 16A to 16R. Raise 16D.

  On the other hand, when the on operation of the down button 41D of the normal operation switch 41 by the operator is transmitted to the control unit 30, the control unit 30 sends a down operation signal resulting from the on operation of the down button 41D to the on operation of the down button 41D. It outputs for the same time length as the ON state continuation time, and drives the lowering solenoid valve provided in, for example, the pneumatic unit of the lowering drive unit 51D. As a result, the lowering solenoid valve of the pneumatic unit extends the relief valve cylinder, inserts the conduction path of the relief valve into the discharge line of the hydraulic cylinder, and applies a lift load acting on each of the lift arms 16A to 16D. The hydraulic cylinders are contracted to lower the lifters 15L and 15R and the lift arms 16A to 16D.

  The control means 30 outputs detected load signals corresponding to the detected loads A to D of the load sensors 24 (24A to 24D) provided in the vehicle support portions 20A to 20D of the front, rear, left and right lift arms 16A to 16D, respectively. The signal is transmitted via the signal amplification amplifiers 61A to 61D and the A / D converter 62.

  The control means 30 controls the lift arms 16A to 16D based on the fact that the imbalances Fad to Fcd among the detected loads A to D of the load sensors 24A to 24D have reached a certain abnormal imbalance K or more. It is determined that the lift load of the vehicle 1 is abnormally unbalanced and the lift state is in an abnormal state. The abnormal imbalance K is set in the control unit 30 by the setting unit 70.

によって求めるとともに、一定の異常非均衡度Ｋを予め設定されて備える。 The control means 30 calculates the unbalance degrees Fab, Fac, Fbd, and Fcd among the detected loads A to D, for example,

And a predetermined abnormal imbalance K is provided in advance.

  Here, when the abnormal imbalance K is set to a small value, in order to determine that the lift state of the vehicle 1 by each of the lift arms 16A to 16D is not in an abnormal state, variations in the detected loads A to D are required. Small, their differences (AB), (AC), (BD), (CD) should be small and their imbalance Fab, Fac, Fbd, Fcd should be small. However, even if the lift state of the vehicle 1 by each of the lift arms 16A to 16D is not abnormal in actual use, the detected load A of each of the load sensors 24A to 24D provided in each of the vehicle support portions 20A to 20D. As a result, it was found from the results of the demonstration experiment that D varied considerably.

  Therefore, in the lift 10, the stopping position of the vehicle 1 with respect to the floor 11 of the maintenance yard, and how to apply the vehicle support portions 20A to 20D provided on the lift arms 16A to 16D to the lift points 2A to 2D of the vehicle 1 are described. Based on the experimental results obtained by repeating various demonstration experiments performed in a different manner, a general imbalance degree in which the vehicle 1 starts to shake when the vehicle 1 in a lift-up state is pushed by hand by each of the lift arms 16A to 16D. Is defined as the degree of abnormal imbalance K.

  In the present embodiment, based on the following i and ii, the abnormal imbalance K is set to a value selected from 90% or less, more preferably 60% or less, and two or more imbalances are set to the set values. Based on the above, it is determined that the lift state of the vehicle 1 by each of the lift arms 16A to 16D is in an abnormal state.

i. Grounds for selecting the set value of the abnormal imbalance K within the range of 90% or less As a result of the verification experiment using various actual vehicles shown in Table 1, the vehicle 1 in the lift-up state by each of the lift arms 16A to 16D is determined. The occurrence of an abnormal situation in which the vehicle 1 shakes when pushed by hand is based on the fact that two or more imbalance degrees Fab to Fcd have reached 90% or more. That is, if the abnormal imbalance K calculated by the control means 30 is less than 90%, it can be considered that the vehicle 1 is in a lift state which is not an abnormal situation in actual use.

ii. Reason for selecting the set value of the abnormal imbalance K more preferably within the range of 60% or less Regarding the stability of automobiles, a notice specifying details of the safety standards for road transport vehicles [2006.03.27] <Section 1 > Article 8 (stability) states that the sum of the loads applied to the grounding portion of the steering wheel in an empty state and in a loaded state is 20% of the vehicle weight and the vehicle total weight, respectively (18% for three-wheeled vehicles). That's all. " Therefore, when looking at the vehicle 1 which is under the application of such security standards, the load balance between the front wheel side and the rear wheel side of the vehicle 1 regardless of whether the vehicle is a front-wheel drive vehicle or a rear-wheel drive vehicle. Even if the balance is high, the ratio is 80% to 20%. When the vehicle 1 is lifted up by the front lift arms 16A and 16B and the rear lift arms 16C and 16D, the front load sensors 24A and 24B and the rear are used. The unbalance degrees Fac and Fbd between the detected loads A and B and the detected loads C and D of the load sensors 24C and 24D on the side are 60%, respectively. That is, when looking at the vehicle 1 produced under the application of the above security standards, the abnormal imbalance K set in the control means 30 should not exceed 60%, and the abnormal imbalance K is less than 60%. Then, the vehicle 1 is in a stable lift state and can be more reliably regarded as in a lift state that is not an abnormal situation.

  The abnormal imbalance K set in the control means 30 by the power supply cut or the like of the control means 30 becomes an initial set value (for example, 90% or less, or 60% or less) set at the time of shipment of the lift 10 from the manufacturing factory. If the abnormal value is out of the range, the control means 30 forcibly corrects the abnormal imbalance K to the initially set value and makes the above-described abnormality determination.

  However, the set value of the abnormal imbalance K may be set to an appropriate value other than the initial set value such as 90% or less, or 60% or less, for example, depending on the shape of the lower surface of the vehicle 1 and the distortion of the floor 11 of the maintenance yard. It is possible to avoid a situation in which the setting is changed and a lift state that is not abnormal in actual use is determined as an abnormal state and the lift work efficiency is impaired.

  According to the knowledge of the present inventor, from the time when the load sensors 24A to 24D of at least one of the plurality of lift arms 16A to 16D detect the lift loads A to D first, By the time the vehicle support portions 20A to 20D of all the lift arms 16A to 16D support the vehicle 1, each of the lift arms 16A to 16D needs to rise above a certain height range (corresponding to the dead zone height H). There is.

  This is because each of the lift arms 16A to 16D manufactured so that the lift points 2A to 2D of the vehicle 1 are substantially on the same plane due to the shape of the lower surface of the vehicle 1 and the distortion of the floor 11 of the maintenance yard. This is due to the fact that the heights made with respect to each other are not uniform. Further, even if the lower surface shape of the vehicle 1 and the floor 11 of the maintenance shop are flat and the heights of the lift points 2A to 2D of the vehicle 1 with respect to the lift arms 16A to 16D are equal, each lift arm This is also because the set height of the rubber receiving portion 23A in the vehicle support portions 20A to 20D of the lift arms 16A to 16D is not necessarily uniform.

  In such a case, the vehicle support portions 20A to 20D of the lift arms 16A to 16D are connected to the respective lift points 2A to 20A on the lower surface of the vehicle 1 in a transitional stage in which the lift of the vehicle 1 is started by the lift arms 16A to 16D. Even if it has already been aligned in 2D, firstly, only one or two of the vehicle supports 20A to 20D of some of the lift arms 16A to 16D hit the corresponding lift points 2A to 2D of the vehicle 1 and the load thereof The sensors 24A to 24D detect the lift loads A to D first. In this lift transition stage, the vehicle support portions 20A to 20D of the other lift arms 16A to 16D are still provided with gaps with respect to the corresponding lift points 2A to 2D of the vehicle 1, and are provided on the vehicle support portions 20A to 20D. Naturally, the detected loads of the load sensors 24A to 24D are still zero, and the imbalance between the detected loads of the load sensors 24A to 24D naturally shows a large abnormal value close to 100%.

  Thereafter, when each of the lift arms 16A to 16D rises above a certain height, the vehicle 1 is displaced in its posture while being lifted up by at least a part of the lift arms 16A to 16D described above, and the other lift arms 16A to 16D In the steady state in which the vehicle support portions 20A to 20D of the vehicle 1 hit the corresponding lift points 2A to 2D of the vehicle 1 and the vehicle support portions 20A to 20D of all the lift arms 16A to 16D hit the corresponding lift points 2A to 2D of the vehicle 1. It is highly probable that the load sensors 24A to 24D will detect the lift loads A to D.

  Therefore, in the lift 10, the stopping position of the vehicle 1 with respect to the floor 11 of the maintenance yard, and how to apply the vehicle support portions 20A to 20D provided on the lift arms 16A to 16D to the lift points 2A to 2D of the vehicle 1 are described. Based on the experimental results obtained by repeating various verification experiments performed by changing, the load sensors 24A to 24D of at least one of the plurality of lift arms 16A to 16D detect the lift loads A to D first. , The general range of lift heights of each lift arm 16A-16D until it can be assumed that the vehicle supports 20A-20D of all lift arms 16A-16D will support the vehicle 1. Shall be defined as

  In other words, the control unit 30 determines that all of the lift arms 16A to 16D have been detected since the load sensors 24A to 24D of at least one of the lift arms 16A to 16D first detected the lift loads A to D. The height range of each of the lift arms 16A to 16D until it is assumed that the vehicle support portions 20A to 20D will support the vehicle 1 is defined as a dead zone height H, and the lift arms 16A to 16D are raised and lowered. When the position is above the dead zone height H, it is estimated that the vehicle support portions 20A to 20D of all the lift arms 16A to 16D have supported the vehicle 1, and the lift arms 16A to 16D It is determined whether or not the lift state of the vehicle 1 by 16D is in the abnormal state described above. The dead zone height H is set in the control unit 30 by the setting unit 70.

  In the present embodiment, the dead zone height H is set to a value selected from the range of 30 mm to 60 mm based on the following i and ii.

i. Grounds for setting lower limit of dead zone height H to 30 mm As a result of a verification experiment using various actual vehicles shown in Table 2, lift points (2A, 2B and 2C) before and after vehicle 1 due to the lower surface shape of vehicle 1 The uneven amount of height in 2D) was at most 20 mm. Here, the uneven amount of the height of the left and right lift points (2A, 2C and 2B, 2D) of the vehicle 1 due to the lower surface shape of the vehicle 1 is determined by the front and rear lift points (2A, 2B and 2C) of the vehicle 1. , 2D) is smaller than the unequal height. Also, due to variations in the construction accuracy of the floor 11 of the maintenance yard and the manufacturing accuracy of the lift 10, the uneven amount of the height that each of the lift points 2A to 2D of the vehicle 1 makes with respect to each of the lift arms 16A to 16D is , About 10 mm. Therefore, the lower limit of the dead zone height H is set to 20 + 10 = 30 mm.

  ii. Due to the shape of the lower surface of the vehicle 1 and the distortion of the floor 11 of the maintenance yard, etc., the unequal amount of height that each of the lift points 2A to 2D of the vehicle 1 makes with respect to each of the lift arms 16A to 16D depends on the actual vehicle 1 Depending on the maintenance site, the above i. It is also possible that it will appear if it does not fit within 30mm. Therefore, the upper limit value of the dead zone height H is set to 60 mm in order to eliminate unreasonable abnormal determination in the transition stage of the lift operation and to surely improve the lift operation efficiency.

  The dead zone height H set in the control means 30 by the power supply cut or the like of the control means 30 is set to an initial set value (a value selected from the range of 30 mm to 60 mm) set at the time of shipment from the manufacturing factory of the lift 10. In the case of an abnormal value outside, the control means 30 forcibly corrects the dead zone height H to the initially set value and makes the above-described abnormality determination.

  However, the set value of the dead zone height H is changed to an appropriate value other than the initial set value set within the range of, for example, 30 mm to 60 mm, depending on the shape of the lower surface of the vehicle 1 and the distortion of the floor 11 of the maintenance shop. Then, an appropriate dead zone height H is selected in actual use to improve the lift work efficiency.

  At this time, the control means 30 has an ascending and descending position detection sensor 52 of each of the elevating bodies 15L and 15R (each of the lift arms 16A to 16D) which moves up and down in synchronization. Accordingly, the control unit 30 detects the load signal detected by each of the load sensors 24A to 24D during the lifting and lowering work of each of the lifting and lowering bodies 15L and 15R and each of the lifting arms 16A to 16D by the lifting driving unit 51U and the lowering driving unit 51D. The vertical position signal detected by the position detection sensor 52 is captured. Then, when the lift position of each of the lift arms 16A to 16D detected by the lift position detection sensor 52 is at a position exceeding the dead zone height H, the control means 30 controls the vehicle support portions 20A of all the lift arms 16A to 16D. 20D are assumed to have supported the vehicle 1, and the imbalances Fab, Fac, Fbd, and Fcd among the detected loads A to D of the load sensors 24A to 24D are constant abnormal imbalance K. Based on the above, it is determined that the lift load of the vehicle 1 by each of the lift arms 16A to 16D is in an abnormal imbalance state and the lift state is in an abnormal state.

  Note that the control means 30 is not limited to determining whether the lifting position of each of the lift arms 16A to 16D exceeds the dead zone height H using the detection result of the lifting position detection sensor 52, The determination may be made using a detection result of a limit switch or the like installed at a position corresponding to the dead zone height H on the lifting path of each of the lifting bodies 15L and 15R or each of the lifting arms 16A to 16D.

  When it is determined that the lift state of the vehicle 1 is in the abnormal state during the lift operation of the vehicle 1 by each of the lift arms 16A to 16D, the control means 30 sounds an alarm sound by the buzzer 71 and warns the display 72. A message is displayed, and the up and down movement of each of the lift arms 16A to 16D is stopped by controlling the up drive unit 51U and the down drive unit 51D.

  In addition, the control means 30 controls the lift arms 16A to 16D while the lift positions of the lift arms 16A to 16D exceed the dead zone height H and stops the lift arms 16A to 16D. When it is determined that the lift state of the vehicle 1 is abnormal, the lift arms 16A to 16D can be lowered only by a special operation applied to a special button 42S provided as a special operation switch 42 in the operation unit 40. Such an abnormal situation may occur during heavy maintenance work such as engine lowering work performed by positioning the vehicle 1 at a certain lift work position by each of the lift arms 16A to 16D, and the operator is not provided with the down button 41D. By using the special button 42S, it is intended to respond with more special attention than usual.

Therefore, according to the present embodiment, the following operational effects can be obtained.
(a) From the time when the load sensors 24A to 24D of at least one of the plurality of lift arms 16A to 16D first detect the lift loads A to D, the vehicle support portions of all the lift arms 16A to 16D The lift height of each of the lift arms 16A to 16D until it is assumed that the lift arms 20A to 20D will support the vehicle 1 is defined as a dead zone height H, and the lift position of each of the lift arms 16A to 16D is determined as the dead zone height H. It is estimated that the vehicle support portions 20A to 20D of all the lift arms 16A to 16D have reached the steady state of the lift for supporting the vehicle 1 when the vehicle 1 is at the position exceeding It is determined whether the lift state is abnormal.

  Accordingly, when the lift position of each of the lift arms 16A to 16D does not reach the dead zone height H, the control means 30 determines that each of the lift arms 16A to 16D is still in the aforementioned lift transition stage with respect to the vehicle 1 and that each of the load sensors It is determined that the imbalances Fab, Fac, Fbd, and Fcd between the detected loads A to D of 24A to 24D tend to show abnormal values that are above a certain abnormal imbalance K. Irrational abnormality determination based on the abnormal value in the lift transition stage is not performed.

  When the lift position of each of the lift arms 16A to 16D exceeds the dead zone height H, the control means 30 determines that the vehicle support portions 20A to 20D of all of the lift arms 16A to 16D have the corresponding lift of the vehicle 1. It is estimated that the lift steady stage corresponding to the point has been reached, and whether the unbalanced levels Fab, Fac, Fbd, Fcd of the detected loads A to D of the load sensors 24A to 24D have reached a certain abnormal unbalanced degree K or more. Is calculated, and based on the calculation result, it is determined whether or not the lift loads A to D of the vehicle 1 supported by the lift arms 16A to 16D are in an abnormal imbalance state and the lift state is in an abnormal state. Is reasonably determined.

  Thus, even if the lift state of the vehicle 1 by the lift arms 16A to 16D is not abnormal in actual use, the lift loads A to D of the vehicle 1 by the lift arms 16A to 16D are in an abnormally unbalanced state. Therefore, the frequency at which the lift state is determined to be in an abnormal state is rationally reduced, and the lift-up / down of the vehicle 1 is repeated every time the abnormality is determined, and the abnormality determination operation is not repeated without anybody. Improve the work efficiency of vehicle maintenance.

  (b) The control means 30 raises and lowers each of the lift arms 16A to 16D when it is determined that the lift state of the vehicle 1 is abnormal during the lift operation of the vehicle 1 by each of the lift arms 16A to 16D according to the above (a). To stop.

  (c) The control means 30 determines that each of the lift arms 16A to 16D is at a position exceeding the dead zone height H, and that the lift arms 16A to 16D stop lifting and lowering each of the lift arms 16A to 16D. When it is determined that the lift state of the vehicle 1 by the lift arms 16A to 16D is in an abnormal state, the lift arms 16A to 16D can be lowered only by a special operation using the special button 42S.

  (d) The control means 30 sets the dead zone height H of the lift position of each of the lift arms 16A to 16D to a set value selected from the range of 30 mm to 60 mm. Thus, the control means 30 rationally determines the abnormal imbalance state of the lifted-up vehicle 1.

  (e) When the vehicle maintenance lift has four front, rear, left and right lift arms 16A to 16D, the control means 30 controls the load sensors 24A to 24A provided on the vehicle support portions 20A to 20D of the lift arms 16A to 16D, respectively. An abnormality in which two or more Fab to Fcd are selected and set within a range of 90% or less, more preferably 60% or less, among imbalance degrees Fab to Fcd among the detected loads A to D of 24D. When the imbalance degree K or more is reached, it is determined that the lift state of the vehicle 1 by each of the lift arms 16A to 16D is in an abnormal state. As a result, the control means 30 rationally determines an abnormal imbalance state where the vehicle 1 shakes when the lifted-up vehicle 1 is pushed by hand.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. Included in the present invention.

  According to the present invention, in a vehicle maintenance lift, it is rationally determined whether or not the lift load of the vehicle supported by each lift arm is in an abnormally unbalanced state and the lift state is in an abnormal state. Maintenance work efficiency can be improved.

DESCRIPTION OF SYMBOLS 1 Vehicle 2A to 2D Lift point 10 Vehicle maintenance lift 16A to 16D Lift arm 20A to 20D Vehicle support 24A to 24D Load sensor 30 Control means A to D Detected loads Fab, Fac, Fbd, Fcd Unbalanced degree K Abnormal unbalanced Degree H dead zone height

Claims (5)

Perform a lift operation to support the vehicle by a vehicle support provided in each of a plurality of lift arms that move up and down in synchronization, and provide a load sensor in each of the vehicle supports of each lift arm,
Control means is provided for determining that the lift state of the vehicle by each lift arm is in an abnormal state based on that the imbalance between the detected loads of the load sensors has reached a certain abnormal imbalance or more. A vehicle maintenance lift,
The control means includes:
From the time when the load sensor of at least one of the plurality of lift arms first detects the lift load to the time when it is assumed that the vehicle supports of all the lift arms will support the vehicle. Determine the range of height of each lift arm as dead zone height,
When the lift position of each lift arm exceeds the above dead zone height, it is estimated that the vehicle support portions of all lift arms have supported the vehicle, and the vehicle lift state by each lift arm A vehicle maintenance lift for determining whether or not the vehicle is in the above-mentioned abnormal situation.   2. The vehicle maintenance lift according to claim 1, wherein the control unit stops lifting and lowering of each lift arm when the control unit determines that the lift state is in the abnormal state during a lift operation of the vehicle by each lift arm. 3.   The control means may be configured such that the lift position of each lift arm is at a position exceeding the dead zone height, and the lift state of the vehicle by each lift arm is in the abnormal state while the lift arms are stopped. 2. The vehicle maintenance lift according to claim 1, wherein when it is determined that each of the lift arms can be lowered only by a special operation.   The vehicle maintenance lift according to any one of claims 1 to 3, wherein the control means sets a dead zone height of each lift arm to a set value selected from a range of 30 mm to 60 mm. It has four front, rear, left and right lift arms,
The control means, when the detected loads of the load sensors provided on the vehicle support portions of the lift arms are A to D, the imbalance degrees Fab, Fac, Fbd, Fcd among the detected loads A to D, respectively. To

And the abnormal imbalance is set to a set value selected from a range of 90% or less, more preferably 60% or less, and the two or more imbalances reach the set value or more. The vehicle maintenance lift according to any one of claims 1 to 4, wherein it is determined that the lift state of the vehicle by each lift arm is abnormal.

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