CN108320659A - A kind of analog demenstration mechanism of factory safety equipment - Google Patents

Abstract

The present invention relates to a kind of analog demenstration mechanisms of factory safety equipment, drawstring including cabinet and through cabinet top, one end that drawstring is located at cabinet is connected with pouring weight, the other end vertically in the outside of cabinet and is connected with pulling handle by pulley, cabinet top and the position of pulley cooperation are provided with smooth set, control piece feeding port is offered on the cabinet side plate opposite with handle is pulled and is combined with control piece feeding device, control piece feeding device includes that the control piece feeding cylinder being horizontally orientated on the outside of cabinet is arranged, control piece feeding cylinder is connected with control piece feeding movable block, control piece feeding movable block is connected with the control piece connection shaft penetrated into cabinet, the control piece connection shaft is connected with elastic control piece；The automatic charging and retraction of control piece may be implemented by control piece feeding device by the present invention, and then induced test and model comparison free switching may be implemented, and only need elastic control piece that control can be completed, and save the structure of manikin.

Description

A kind of analog demenstration mechanism of factory safety equipment

Technical field

The present invention relates to the analog demenstration mechanisms that rote teaching apparatus field more particularly to a kind of factory safety are equipped.

Background technology

With the propulsion of mechanization process, the student of machinery field is increasing, since factory is with a variety of uncertain Risk factor, many schools all can carry out safe teaching to student mostly, in order to improve the effect of teaching, most preferably carry out certainly Body tests the importance of safety equipment, therefore some teaching demonstration equipments occurs, and wherein safety cap demonstration mechanism is most common Teaching demonstration mechanism, the existing most very simple of teaching demonstration mechanism is exactly that drawstring holds a pouring weight, makes pouring weight Certain altitude by circle under the movement of falling object on the helmet for students of safe wearing cap, thus student is allowed to experience safety Cap acts on, and then safe wearing cap, but existing this kind of teaching demonstration mechanism is there are certain defect, check experiment need by Manikin is moved in cabinet, inconvenient for operation, and needs complete manikin, and must ensure Sheffield dummy head Position below has the function of rigid support, so could intuitively show the deformation amplitude of elasticity control head, complicated, takes Put inconvenience.

Invention content

The object of the present invention is to provide a kind of analog demenstration mechanisms of factory safety equipment, can by control piece feeding device To realize the automatic charging and retraction of control piece, and then induced test and model comparison free switching may be implemented, and only needs Control can be completed in elastic control piece, saves the structure of manikin.

In order to achieve the goal above, the technical solution adopted by the present invention is：A kind of analog demenstration machine of factory safety equipment Structure, including cabinet and the drawstring through cabinet top, one end that the drawstring is located at cabinet is connected with pouring weight, the other end passes through Pulley vertically in the outside of cabinet and is connected with pulling handle, and the cabinet top is provided with smooth with the position that pulley coordinates It covers, control piece feeding port is offered on the cabinet side plate opposite with handle is pulled and is combined with control piece feeding device, The control piece feeding device includes that the control piece feeding cylinder being horizontally orientated on the outside of cabinet is arranged, on the control piece Material cylinder is connected with control piece feeding movable block, and the control piece feeding movable block is connected with the control piece penetrated into cabinet Shaft is connected, control piece connection shaft is connected with elastic control piece.

Further, safety cap clamping device is provided in the cabinet, the safety cap clamping device includes setting The safety cap gripper cylinder in cabinet relative inner is set, the safety cap gripper cylinder is connected with safety cap clamping inserted block, peace The both sides of full cap are fixed with safety cap clamping sleeve, and sleeve and safety cap clamping inserted block sleeve cooperation is clamped in the safety cap, And safety cap clamping inserted block is square block.

Further, control piece rotary electric machine, the control piece are provided on the inside of the control piece feeding cylinder Coupling band is socketed on the output shaft of rotary electric machine, the control piece connects shaft and coordinates with coupling band sleeve, and control piece Connection shaft is square pole, and the upper and lower that the cabinet is located at control piece feeding port is provided with connection shaft clamping mounting blocks, The connection shaft clamping mounting blocks be equipped with connection shaft clamping cylinder, the connection shaft clamping cylinder be connected with The connection shaft clamping half that control piece connects shaft cooperation covers.

Further, the interior lower part of the cabinet, which is provided with, tramples lifting gear, and the lifting gear of trampling includes Lifting cylinder of trampling in bottom of cabinet bulk is set, and described trampling is provided with pedal, the bottom of the cabinet on lifting cylinder Portion be provided centrally with output shaft it is upward trample lifting motor, the output shaft for trampling lifting motor is threaded rod, described Pedal below be provided with and trample the output shaft screw-thread fit of lifting motor and trample lifting swivel nut.

Further, pouring weight limit coordinating block is provided on the outside of the pouring weight, be provided in the cabinet with again Block limits the pouring weight limiting device of coordinating block cooperation, and the pouring weight limiting device includes the pouring weight limit peace being arranged in cabinet Block is filled, the pouring weight, which is mounted below block, is provided with pouring weight limit adjusting cylinder, and pouring weight limit adjusts cylinder Lower section is connected with pouring weight limited block, and aperture is offered in the middle part of the pouring weight limited block and is mounted less than pouring weight more than pouring weight First matching hole of block.

Further, pouring weight limit, which is adjusted, is provided with pouring weight limit adjusting block, the pouring weight below cylinder The lower section for limiting adjusting block is connected with pouring weight limited block by pouring weight limit spring, is opened in the middle part of pouring weight limit adjusting block It is more than the second matching hole that block is mounted in pouring weight equipped with aperture.

Further, the upper surface of the pouring weight limited block be fixed with across pouring weight limit adjusting block pouring weight limit lead To bar, the upper end of the pouring weight limition orientation bar is provided with pouring weight limit and intercepts block.

Further, the pouring weight limit spring is provided at both ends with limit spring mounting blocks, pouring weight limit It is provided on the downside of the upside of block and pouring weight limit adjusting block and pacifies with the limit spring of limit spring mounting blocks screw thread socket cooperation Fill stud.

Further, the outside of the cabinet is vertically evenly provided with limits with the handle of handle cooperation is pulled Position device, the handle limiting device includes the handle limit folding slot of the anterior-posterior horizontal trend opened up on the outside of cabinet, described Handle limit folding slot in the middle part of be embedded with the front and back handle limit folding cylinder moved towards, handle limit folding cylinder Front and back end be connected with pull handle cooperation handle limited block.

Further, handle limit cooperation inserting column, the pulling handle are provided with below the handle limited block Top offers the handle limit cooperation jack that cooperation inserting column cooperation is limited with handle, and the handle limited block is located at handle limit Position upper and lower sides in position folding slot are embedded with the handle limit ball that the folding tangent cooperation of slot is limited with handle.

Beneficial effects of the present invention are：

1, the automatic charging and retraction of control piece may be implemented by control piece feeding device, so may be implemented induced test and Model comparison free switching, and only need elastic control piece that control can be completed, save the structure of manikin.

2, the design of safety cap clamping device, the wearing of convenient and safe cap and picks and places, and can realize a safety cap Realize the continuous use of multiple experiencers.

3, the design of control piece rotating part can make the feeding of control piece not generate interference with safety cap clamping device, Connect the design of shaft gripping part, it can be ensured that make connection shaft be not in rotation carrying out experiment, it is ensured that check experiment Effect, while can avoid that rotary electric machine damage will be compareed.

4, the design of lifting gear is trampled, the height of pedal can be adjusted according to the experiencer of different heights, and then can be with Preferably cooperation safety cap clamping device realizes the automatic wearing of safety cap, and the lifting structure for trampling lifting gear is ingenious, energy It is enough effectively to avoid stepping on the case where collapsing.

5, the structure design of pouring weight limiting device, the amplitude that pouring weight can be avoided to fall by pouring weight limited block is excessive, makes Cause experiencer injured at accident.

6, the design of pouring weight limit spring makes pouring weight limited block realize good buffering when being limited to pouring weight, keeps away Exempting from generation hard collision causes parts damages, pouring weight limition orientation bar and pouring weight limit to intercept the design of block, can limit buffering Amplitude, avoid whereabouts amplitude excessive, while can play the role of guiding to pouring weight limited block again.

7, the design of limit spring mounting blocks and limit spring installation stud, can facilitate the dismounting of pouring weight limit spring, And then it is convenient for changing.

8, the design of handle limiting device can preferably determine the rough location and movable amplitude for pulling handle, in turn The generation of safety accident can preferably be avoided.

9, handle limit folding slot cooperation handle limits ball, can preferably facilitate the activity of handle limited block.

Description of the drawings

Fig. 1 is a kind of structural schematic diagram of the analog demenstration mechanism of factory safety equipment.

Fig. 2 is the structural schematic diagram of control piece feeding device.

Fig. 3 is the structural schematic diagram for trampling lifting gear.

Fig. 4 is the structural schematic diagram of safety cap clamping device.

Fig. 5 is the sectional view of A-A in Fig. 1.

Fig. 6 is the sectional view of B-B in Fig. 5.

Fig. 7 is the structural schematic diagram of pouring weight limiting device.

Fig. 8 is the partial enlarged view of C in Fig. 7.

Label character described in figure is expressed as：1, cabinet；2, lifting gear is trampled；3, drawstring；4, smooth set；5, pouring weight； 6, pouring weight limits coordinating block；7, handle is pulled；8, pouring weight limiting device；9, handle limiting device；10, safety cap；11, safety cap Clamping device；12, control piece feeding device；13, lifting cylinder is trampled；14, pedal；15, lifting motor is trampled；16, it tramples Lift swivel nut；17, pulley；18, handle limit folding slot；19, handle limit folding cylinder；20, handle limited block；21, handle Limit cooperation jack；22, handle limit cooperation inserting column；23, handle limits ball；25, safety cap gripper cylinder；26, safety cap Inserted block is clamped；27, sleeve is clamped in safety cap；31, block is mounted in pouring weight；32, pouring weight limit adjusts cylinder；33, pouring weight limits Adjusting block；34, pouring weight limited block；35, pouring weight limit spring；36, limit spring mounting blocks；37, limit spring installs stud； 38, pouring weight limition orientation bar；39, pouring weight limit intercepts block；41, control piece feeding port；42, control piece feeding cylinder；43, it compares Part feeding movable block；44, control piece rotary electric machine；45, coupling band；46, control piece connects shaft；47, elastic control piece；48、 Connect shaft clamping mounting blocks；49, shaft clamping cylinder is connected；50, connection shaft clamping half covers.

Specific implementation mode

In order to make those skilled in the art more fully understand technical scheme of the present invention, below in conjunction with the accompanying drawings to the present invention into The description of row detailed description, this part is only exemplary and explanatory, should not there is any limitation to protection scope of the present invention Effect.

As Figure 1-Figure 8, concrete structure of the invention is：A kind of analog demenstration mechanism of factory safety equipment, including Cabinet 1 and drawstring 3 through cabinet top, one end that the drawstring is located at cabinet 1 are connected with pouring weight 5, the other end by sliding Wheel 17 vertically in the outside of cabinet 1 and is connected with pulling handle 7, and 1 top of cabinet is arranged with the position that pulley 17 coordinates There is a smooth set 4, the cabinet 1 is compareed with offering control piece feeding port 41 on the opposite side plate of pulling handle 7 and be combined with Part feeding device 42, the control piece feeding device 42 include that the control piece feeding gas being horizontally orientated in 1 outside of cabinet is arranged Cylinder 42, the control piece feeding cylinder 42 are connected with control piece feeding movable block 43, the control piece feeding movable block 43 It is connected with the control piece connection shaft 46 penetrated into cabinet 1, control piece connection shaft 46 connects flexible control piece 47。

Preferably, safety cap clamping device 11 is provided in the cabinet 1, the safety cap clamping device 11 includes Safety cap gripper cylinder 25 in 1 relative inner of cabinet is set, and the safety cap gripper cylinder 25 is connected with safety cap clamping The both sides of inserted block 26, safety cap 10 are fixed with safety cap clamping sleeve 27, and sleeve 27 and safety cap folder is clamped in the safety cap The cooperation of 26 sleeve of inserted block is held, and safety cap clamping inserted block 26 is square block.

Preferably, the inside of the control piece feeding cylinder 42 is provided with control piece rotary electric machine 44, the control Coupling band 45 is socketed on the output shaft of part rotary electric machine 44, control piece connection shaft 45 is matched with 45 sleeve of coupling band It closes, and control piece connection shaft 45 is square pole, the upper and lower that the cabinet 1 is located at control piece feeding port 41 is provided with connection Shaft clamping mounting blocks 48, the connection shaft clamping mounting blocks 48 are equipped with connection shaft clamping cylinder 49, the company Spindle bar clamping cylinder 49 is connected with half set 50 of connection shaft clamping that the cooperation of shaft 46 is connect with control piece.

Preferably, the interior lower part of the cabinet 1, which is provided with, tramples lifting gear 2, and the lifting gear 2 of trampling includes It is arranged and tramples lifting cylinder 13 in 1 bottom of cabinet, described trampling is provided with pedal 14, the cabinet on lifting cylinder 13 The bottom centre of body 1 be provided with output shaft it is upward trample lifting motor 15, the output shaft for trampling lifting motor 15 is Threaded rod, what the lower section of the pedal 14 was provided with and trampled the output shaft screw-thread fit of lifting motor 15 tramples lifting spiral shell Set 16.

Preferably, the outside of the pouring weight 4 is provided with pouring weight limit coordinating block 6, be provided in the cabinet 1 with again Block limits the pouring weight limiting device 8 that coordinating block 6 coordinates, and the pouring weight limiting device 8 includes the pouring weight limit being arranged in cabinet 1 Position mounting blocks 31, the pouring weight are mounted 31 lower section of block and are provided with pouring weight limit adjusting cylinder 32, pouring weight limit The lower section for adjusting cylinder 32 is connected with pouring weight limited block 34, and the middle part of the pouring weight limited block 34 offers aperture and is more than pouring weight 5 are less than the first matching hole that block 31 is mounted in pouring weight.

Preferably, the lower section of pouring weight limit adjusting cylinder 32 is provided with pouring weight limit adjusting block 33, the weight The lower section of block limit adjusting block 33 is connected with pouring weight limited block 34 by pouring weight limit spring 35, and the pouring weight limits adjusting block 33 middle part offers the second matching hole that block 31 is mounted more than pouring weight for aperture.

Preferably, the upper surface of the pouring weight limited block 34 is fixed with the pouring weight limit that adjusting block 33 is limited across pouring weight Guide rod 38, the upper end of the pouring weight limition orientation bar 38 are provided with pouring weight limit and intercept block 39.

Preferably, the pouring weight limit spring 35 is provided at both ends with limit spring mounting blocks 36, pouring weight limit The upside of position block 34 and the downside of pouring weight limit adjusting block 33 are provided with the limit with the socket cooperation of 36 screw thread of limit spring mounting blocks Position spring installs stud 37.

Preferably, the outside of the cabinet 1 is vertically evenly provided with limits with the handle for pulling handle 7 to coordinate Position device 9, the handle limiting device 9 include the handle limit folding slot 18 for the anterior-posterior horizontal trend that 1 outside of cabinet opens up, The middle part of the handle limit folding slot 18 is embedded with the front and back handle limit folding cylinder 19 moved towards, handle limit The front and back end of folding cylinder 19 is connected with the handle limited block 20 coordinated with pulling handle 7.

Preferably, the lower section of the handle limited block 20 is provided with handle limit cooperation inserting column 22, the pulling hand 7 top of handle is offered limits the handle limit cooperation jack 21 that cooperation inserting column 22 coordinates, the handle limited block 20 with handle Position upper and lower sides in handle limit folding slot 18 are embedded with the handle limit that folding 18 tangent cooperation of slot is limited with handle Ball 23.

When specifically used, first equipment is assembled, each handle limiting device 9 is in station state, pouring weight limit at this time Position coordinating block is in suitable position, pulls handle 7 by undermost 20 interception post of handle limited block, is then compareed successively Experiment and students experience；

Check experiment is as follows：43 activity of control piece feeding movable block is driven by control piece feeding cylinder 42, and then drives control Part connects shaft 46 and elastic control piece 47 penetrates into cabinet, drives control piece to connect by control piece rotary electric machine 44 again later Spindle bar 46 rotates 180 degree, and then adjusts the angle of elastic control piece 47, completes the blowing of elastic control piece, later basis Experiment demand, to the handle limiting device 9 for pulling handle 7 to be intercepted when selecting experiment, by this handle limiting device and most Handle limiting device between lower layer's handle limiting device is opened, i.e., limiting folding cylinder 19 by handle limits two pieces of handles Block 20 struts, and then again opens undermost handle limit closing device 9, so that pouring weight is done the movement of falling object, in blanking Pouring weight 5 strikes elastic control piece after pouring weight limit spring 35 is pulled down certain amplitude by pouring weight limit coordinating block 6 in journey, observes bullet Property control piece amplitude of deformation, experience pouring weight fall when shock injury, complete check experiment, by control piece feeding device 12 Homing；

Students experience is as follows：First safety cap 10 is put well, drives safety cap that inserted block 26 is clamped by safety cap gripper cylinder 25 and wears Enter to safety cap and sleeve 27 is clamped, safety cap is clamped, then makes student station on pedal 14, by trampling lifting electricity Machine 15 and the synergistic effect for trampling lifting cylinder 13 make pedal 14 steadily rise, until the head of experience student is nested into safety In cap 10, then makes safety cap that inserted block 26 be clamped by safety cap gripper cylinder 25 and the release of sleeve 27 is clamped with safety cap, later According to experiment demand, to the handle limiting device 9 for pulling handle 7 to be intercepted when selecting experiment, by this handle limiting device Handle limiting device between lowest level handle limiting device is opened, i.e., limits folding cylinder 19 by two pieces of handles by handle Limited block 20 struts, and then again opens undermost handle limit closing device 9, so that pouring weight is done the movement of falling object, under Pouring weight 5 strikes on safety cap 10 after pouring weight limit spring 35 is pulled down certain amplitude by pouring weight limit coordinating block 6 during material, pacifies Full cap protection student bears the shock injury of pouring weight whereabouts, allows students' response to the function and importance of safety cap, with personal body Test the importance that factory's safe wearing cap is carried out to student.

It should be noted that herein, the terms "include", "comprise" or its any other variant are intended to non-row His property includes, so that the process, method, article or equipment including a series of elements includes not only those elements, and And further include other elements that are not explicitly listed, or further include for this process, method, article or equipment institute it is intrinsic Element.

Principle and implementation of the present invention are described for specific case used herein, the explanation of above example It is merely used to help understand the method and its core concept of the present invention.The above is only a preferred embodiment of the present invention, it answers When pointing out due to the finiteness of literal expression, and objectively there is unlimited concrete structure, for the common skill of the art For art personnel, without departing from the principle of the present invention, several improvement, retouching or variation can also be made, can also incited somebody to action Above-mentioned technical characteristic is combined in the right way；These improve retouching, variation or combination, or the not improved structure by invention Think and technical solution directly applies to other occasions, is regarded as protection scope of the present invention.

Claims (10)

1. a kind of analog demenstration mechanism of factory safety equipment, including cabinet（1）With the drawstring through cabinet top（3）, described Drawstring be located at cabinet（1）One end be connected with pouring weight（5）, the other end pass through pulley（17）Vertically in cabinet（1）Outside simultaneously It is connected with pulling handle（7）, which is characterized in that the cabinet（1）Top and pulley（17）The position of cooperation is provided with smooth Set（4）, the cabinet（1）With pulling handle（7）Control piece feeding port is offered on opposite side plate（41）And it is combined with pair According to part feeding device（42）, the control piece feeding device（42）Including being arranged in cabinet（1）The control that outside is horizontally orientated to Part feeding cylinder（42）, the control piece feeding cylinder（42）It is connected with control piece feeding movable block（43）, the control Part feeding movable block（43）It is connected with and penetrates into cabinet（1）Interior control piece connects shaft（46）, the control piece connecting shaft Bar（46）Connect flexible control piece（47）.

2. a kind of analog demenstration mechanism of factory safety equipment according to claim 1, which is characterized in that the cabinet （1）Inside it is provided with safety cap clamping device（11）, the safety cap clamping device（11）Including being arranged in cabinet（1）In relatively The safety cap gripper cylinder of side（25）, the safety cap gripper cylinder（25）It is connected with safety cap clamping inserted block（26）, safety Cap（10）Both sides be fixed with safety cap clamping sleeve（27）, sleeve is clamped in the safety cap（27）Inserted block is clamped with safety cap （26）Sleeve coordinates, and inserted block is clamped in safety cap（26）For square block.

3. a kind of analog demenstration mechanism of factory safety equipment according to claim 2, which is characterized in that the control Part feeding cylinder（42）Inside be provided with control piece rotary electric machine（44）, the control piece rotary electric machine（44）Output shaft On be socketed with coupling band（45）, the control piece connects shaft（45）With coupling band（45）Sleeve coordinates, and control piece connects Shaft（45）For square pole, the cabinet（1）Positioned at control piece feeding port（41）Upper and lower be provided with connection shaft clamping Mounting blocks（48）, the connection shaft clamping mounting blocks（48）Connection shaft clamping cylinder is installed（49）, the connection Shaft clamping cylinder（49）It is connected with and connect shaft with control piece（46）The connection shaft clamping of cooperation half covers（50）.

4. a kind of analog demenstration mechanism of factory safety equipment according to claim 1, which is characterized in that the cabinet （1）Interior lower part be provided with and trample lifting gear（2）, described tramples lifting gear（2）Including being arranged in cabinet（1）Bottom Trample lifting cylinder（13）, described tramples lifting cylinder（13）On be provided with pedal（14）, the cabinet（1）Bottom Be provided centrally with output shaft it is upward trample lifting motor（15）, described tramples lifting motor（15）Output shaft be screw thread Bar, the pedal（14）Lower section be provided with and trample lifting motor（15）Output shaft screw-thread fit trample lifting spiral shell Set（16）.

5. a kind of analog demenstration mechanism of factory safety equipment according to claim 4, which is characterized in that the pouring weight （4）Outside be provided with pouring weight limit coordinating block（6）, the cabinet（1）It is inside provided with and limits coordinating block with pouring weight（6）Cooperation Pouring weight limiting device（8）, the pouring weight limiting device（8）Including being arranged in cabinet（1）Block is mounted in interior pouring weight （31）, block is mounted in the pouring weight（31）Lower section is provided with pouring weight limit and adjusts cylinder（32）, the pouring weight, which limits, to be adjusted Displacements of cylinders（32）Lower section be connected with pouring weight limited block（34）, the pouring weight limited block（34）Middle part offer aperture and be more than Pouring weight（5）Block is mounted less than pouring weight（31）The first matching hole.

6. a kind of analog demenstration mechanism of factory safety equipment according to claim 5, which is characterized in that the pouring weight Limit adjusts cylinder（32）Lower section be provided with pouring weight limit adjusting block（33）, the pouring weight limits adjusting block（33）Lower section Pass through pouring weight limit spring（35）It is connected with pouring weight limited block（34）, the pouring weight limits adjusting block（33）Middle part offer Aperture is more than pouring weight and block is mounted（31）The second matching hole.

7. a kind of analog demenstration mechanism of factory safety equipment according to claim 6, which is characterized in that the pouring weight Limited block（34）Upper surface be fixed with across pouring weight limit adjusting block（33）Pouring weight limition orientation bar（38）, the pouring weight Limition orientation bar（38）Upper end be provided with pouring weight limit intercept block（39）.

8. a kind of analog demenstration mechanism of factory safety equipment according to claim 6, which is characterized in that the pouring weight Limit spring（35）Be provided at both ends with limit spring mounting blocks（36）, the pouring weight limited block（34）Upside and pouring weight limit Position adjusting block（33）Downside be provided with and limit spring mounting blocks（36）The limit spring of screw thread socket cooperation installs stud （37）.

9. a kind of analog demenstration mechanism of factory safety equipment according to claim 1, which is characterized in that the cabinet （1）Outside be vertically evenly provided with pull handle（7）The handle limiting device of cooperation（9）, the handle Limiting device（9）Including cabinet（1）The handle limit folding slot for the anterior-posterior horizontal trend that outside opens up（18）, the described handle limit Position folding slot（18）Middle part be embedded with the front and back handle limit folding cylinder moved towards（19）, the handle, which limits, opens and closes cylinder （19）Front and back end be connected with pull handle（7）The handle limited block of cooperation（20）.

10. a kind of analog demenstration mechanism of factory safety equipment according to claim 9, which is characterized in that the hand Handle limited block（20）Lower section be provided with handle limit cooperation inserting column（22）, the pulling handle（7）Top offers and hand Handle limit cooperation inserting column（22）The handle limit cooperation jack of cooperation（21）, the handle limited block（20）It is limited positioned at handle Open and close slot（18）Interior position upper and lower sides are embedded with limits folding slot with handle（18）The handle of tangent cooperation limits ball（23）.