擺式摩擦系數(shù)儀,BM-3型擺式摩擦系數(shù)測定儀
擺式摩擦系數(shù)測定儀 用途: 該儀器是河北省虹宇儀器設(shè)備有限公司推出的產(chǎn)品主要用于高等級公路、城市道路及機場跑道抗滑性能的檢測。適用于公路面摩擦系數(shù)測定,可上下調(diào)接。該儀器調(diào)試方便,操作簡單,測試數(shù)據(jù)準確,穩(wěn)定性大大提高,并且室內(nèi)外均可使用,是高等級公路等設(shè)備建設(shè)中*的檢測儀器之一。
BM-3型擺式摩擦系數(shù)測定儀是動力擺沖擊型儀器。它是根據(jù)“擺的位能損失等于擺臂末端橡膠片在路面上滑動時,克服路面摩擦所做的功”這一基本原理研制而成。
BM-3型擺式摩擦系數(shù)測定儀主要技術(shù)參數(shù):
擺重量: 1500g±30g
擺重心矩: 410mm±5mm
橡膠片對路面正向靜壓力: 22.2N / 2263g
擺在橡膠片端部距擺動中尺距: 508mm
擺在路面上滑動長度: 126mm
外形尺寸: 700×360×700mm
儀器重量: 約12kg
擺從傾斜5度處自由放下到擺動停止的次數(shù),應(yīng)不少于70次。
四、擺式摩擦系數(shù)儀,BM-3型擺式摩擦系數(shù)測定儀儀器主要部分有擺動部分和機架部分。
1、2-緊固把手;3-升降把手; 4-釋放開關(guān); 5-轉(zhuǎn)向節(jié)螺蓋; 6-調(diào)節(jié)螺母;7-針簧片或氈墊
8-指針; 9-連接螺母; 10-調(diào)平螺栓; 11-底座; 12-鉸鏈; 13-水準泡; 14-卡環(huán);
15-定位螺絲;16-舉升柄;17-平衡錘;18-并緊螺母;19-滑溜塊;20-橡膠片; 21-止滑螺絲
1、 座:由T型腿,調(diào)平螺絲和水準泡組成。對儀器起調(diào)平,支承作用。
2、 立柱:由立柱、升降機構(gòu),導(dǎo)向桿及儀器把手組成。用于升降和固定擺頭的位置。
3、 釋放開關(guān):安裝于懸臂上的開關(guān)。用于保持擺桿水平位置和釋放擺落下的作用。
4、 擺頭:由緊固把手,擺軸,轉(zhuǎn)向節(jié),軸承等組成,起聯(lián)結(jié)擺、固定位置,保證在擺動平面內(nèi)自由擺動的作用。
5、 示數(shù)系統(tǒng):由指針、毛氈圈、法蘭、緊固螺母及度盤組成,指針可直接指示出摩擦系數(shù)數(shù)值。
6、 擺:由上、下部接頭、擺桿、彈簧、杠桿系、舉升柄、外殼、滑溜塊及橡膠片組成。它對擺動中心有規(guī)定力矩,對路面有規(guī)定壓力,本身前與后,左與右的力矩平衡,它是度量路面的摩擦系數(shù)的尺度。
擺式摩擦系數(shù)儀,BM-3型擺式摩擦系數(shù)測定儀試驗步驟
1、 選點:在測試路段上,滑行車方向的左輪輪跡,選擇有代表性的五個測點,每一測點相距約5~10m,距路面邊緣不應(yīng)小于1m 。
2、 儀器調(diào)平:
① 將儀器置于測點上,并使擺的擺動方向與行車方向一致。
② 轉(zhuǎn)動調(diào)平螺絲,使水準泡居中。
3、 調(diào)零:
(1) 放松固定把手,轉(zhuǎn)動升降把手,使擺升高并能自由擺動,然后旋緊把手。
(2) 將擺向右運動,按下釋放開關(guān)。使卡環(huán)進入釋放開關(guān)槽,并處于水平釋放位置,然后松開釋放開關(guān),此時指針應(yīng)被撥至緊靠撥針片。
(3) 按下釋放開關(guān),擺向左運動,并帶動指針向上運動,當(dāng)擺達到zui高置后下落時,用左手將擺桿接住,此時指針應(yīng)指零。若不指零時,可稍旋緊或放松毛氈圈調(diào)節(jié)螺母。重復(fù)本項操作,直至指針指零。
4、 標(biāo)定滑動長度:
(1) 用刷子清除擺動范圍內(nèi)路面上的松散顆粒和雜物
(2) 讓擺自由懸掛,在橡膠片的外邊平行擺動方向設(shè)置標(biāo)準尺(126mm),放松緊固把手,轉(zhuǎn)動升降把手。使擺緩緩下降,當(dāng)滑溜塊上橡膠片剛接觸路面時,提起舉升柄使滑溜塊升高,將擺向右運動,并轉(zhuǎn)動升降把手使擺下降一段距離,然后放下舉升柄使擺慢慢向左運動,直至橡膠片的邊緣剛剛接觸路面,對正126mm尺的一端,再用手提起舉升柄,使滑溜塊向上抬起,并使擺繼續(xù)向左運動,放下舉升柄,再將擺慢慢向右運動使橡膠片的邊緣再一次接觸路面。橡膠片兩次同路面的接觸點的距離應(yīng)為126mm(滑動長度)。若不符合126mm,可轉(zhuǎn)動升降把手,再重復(fù)上述步驟進行粗調(diào)。當(dāng)基本符合126mm后,旋緊緊固把手,再校正一遍,若滑動長度不符合標(biāo)準時,則升高或降低儀器底座正面的調(diào)平螺絲來校正,但須調(diào)平水準泡。使滑動長度符合要求。爾后,將擺置于水平釋放位置。
5、 測定:用水澆灑路面,并用橡皮刷刷刮,以便洗去泥漿,然后再灑水,并按下釋放開關(guān),使擺在路面上滑過,指針即可指示出路面的摩擦系數(shù)值(一般*次可不作記錄)。當(dāng)擺向回擺時,用左手接住擺桿,右手提起舉升柄使滑溜塊升高,將擺向右運動并按下開關(guān),使擺長環(huán)進入釋放開關(guān),并將擺針撥至緊靠撥針片,重復(fù)此項,測定五次(每次均應(yīng)灑水),記錄每次的數(shù)值。五次數(shù)值差不大于三個單位(即刻度盤的一格半)如差值大于三個單位,應(yīng)檢查產(chǎn)生的原因,并再次重復(fù)上述各項操作,至符合規(guī)定要求為止。
6、測定結(jié)果:
(1)每個測點用五次測定讀數(shù)的平均值代表測點的摩擦系數(shù)值,并用五個測點的摩擦系數(shù)的平均值,代表該測定路段摩擦系數(shù)值。
(2)測定讀數(shù),即該度盤上指針的讀數(shù)(簡稱“擺值”),除以100,即為路面的摩擦系數(shù)。如:擺值33,摩擦系數(shù)即為0.33。
7、擺式摩擦系數(shù)儀,BM-3型擺式摩擦系數(shù)測定儀注意事項:
(1)由于路面的摩擦系數(shù)受季節(jié)和溫度的影響,故應(yīng)記錄測試日期和濕路面的溫度。
(2)測試路段應(yīng)描述路面結(jié)構(gòu)類型、外觀和使用年限。
(3)當(dāng)擺向左擺動后返回時,一定要用手接住擺桿,以免損壞滑溜塊和指針。
(4)在滑溜塊上橡膠片滑動的有效范圍內(nèi)不應(yīng)有明顯的凸形和凹形,以免影響測定數(shù)值。
(5)標(biāo)定滑動長度時,應(yīng)以橡膠片剛剛接觸路面為準,不可借擺的力量向前滑動,以免標(biāo)定的滑動長度過長。
(6)路面摩擦系數(shù)沿公路的橫斷面而變化。通常路中小,路邊大。為反映測試路段的zui不利情況,應(yīng)選擇摩擦系數(shù)小,而使用剎車較頻繁的位置。即沿行車方向的左輪輪跡處。
(7)滑溜塊上采用新橡膠片時,應(yīng)先在干燥路面上測試數(shù)次后再用。橡膠片的摩耗長邊不得超過3.2mm ,短邊不得超過1.6mm(見圖二)。否則應(yīng)更換新橡膠片。此外,橡膠片被油類污染后也不能使用。橡膠片的有效使用期為一年。一年以后不管是否使用過,均不得再作測定使用。因為橡膠要老化,彈性、硬度均發(fā)生變化,影響測試結(jié)果。
圖二、橡膠片zui大磨耗度
六、附件
a) 灑水壺(一只);
b) 橡膠片(四塊);
c) 標(biāo)準尺(一支);
d) 橡皮刷(一把);
e) 三角架(一架);
七、附錄
擺式摩擦系數(shù)儀,BM-3型擺式摩擦系數(shù)測定儀擺式儀的標(biāo)定:
1、 擺的重量——放松擺桿與轉(zhuǎn)向節(jié)的連接螺母,從儀器上取下裝有滑溜塊的擺。稱重準確至g(應(yīng)符合1500g±30g)。
2、 重心——裝有滑溜塊的擺的重心,由將擺置于刀口上的位置來確定。平衡點的試驗位置,連接螺母,應(yīng)固定于擺臂的遠端,得到平衡點后,應(yīng)旋進或旋出平衡錘直到擺殼邊部水平為止,并將平衡點位置作一記號。
3、 擺動中心到重心的距離——把擺重新裝在儀器上,并取下轉(zhuǎn)向節(jié)螺蓋。測量從擺動中心(軸承螺母中心)至重心的距離,準確到mm(應(yīng)符合410mm±mm)。若有差別,可將重心位置置于刀口上,改變力矩調(diào)節(jié)螺母的位置,必要時,也可增減力矩調(diào)節(jié)螺母數(shù)量,但仍應(yīng)符合(1)和(3)的要求,使擺平衡,滿足力矩要求。
4、 壓力標(biāo)定:
(1) 將擺從儀器上取下,使滑溜塊的橡膠片與擺殼周板平行。保證滑溜塊能繞自身的軸轉(zhuǎn)動,而在軸上的竄動量不大于0.2mm。
(2) 將壓力標(biāo)定天平置于試驗臺上,調(diào)平使指針指中。把三角架置于右側(cè)稱盤的后部。擺式儀放在三角架上,用夾塊將擺桿固定在立柱上,使橡膠片對準右稱盤中部并壓下3~5mm,在左稱盤中加1g重量,使天平穩(wěn)定(此時天平指針向右方)。調(diào)節(jié)儀器底座調(diào)平螺絲使指針對準右方20mm處,并注意保持水準泡居中。
(3)然后在左側(cè)稱盤上加標(biāo)定砝碼(2263g),此時指針應(yīng)回零。若指針不回零,則表示橡膠片對路面的壓力過大(指針偏右方)或過?。ㄖ羔樒蠓剑?。取下標(biāo)定擺桿,用螺絲刀插入彈簧引線的槽內(nèi),旋緊或旋松彈簧松緊調(diào)節(jié)螺母,使指針回零。此時應(yīng)注意握緊擺桿,在旋緊和放松調(diào)節(jié)器節(jié)螺母過程中不至于人為對稱盤加載。然后,重新校核壓力,直到加上標(biāo)定砝碼后指針居中為止。(可使用電子秤標(biāo)
BM-3 pendulum coefficient of friction tester uses: This instrument is the latest product of Hebei Province, Hongyu equipment Co., Ltd. is mainly used for high-grade highways, urban roads and the airport runway skid resistance testing. Applies to the road surface friction coefficient of determination, can be lowered then. The instrument is convenient debugging, simple operation, accurate test data, greatly enhanced stability, and can be used indoors and outdoors, is an indispensable one of the testing equipment in the construction of high-grade highways, and other special equipment.
BM-3 pendulum coefficient of friction tester is a dynamic pendulum impact instrument. It is based on "put the potential loss equal to the arm end of the rubber sheet sliding on the road, to overcome this basic principle of the work done by the road surface friction" from the development.
BM-3 pendulum coefficient of friction tester main technical parameters:
Swing weight: 1500g ± 30g
Placed center of gravity moment: 410mm ± 5mm
Rubber sheet on the road forward static pressure: 22.2N / 2263g
Placed in a rubber sheet end from the swing-foot distance: 508mm
Placed on the road sliding length: 126mm
Dimensions: 700 × 360 × 700mm
Weight: about 12kg
Swing free from the tilt 5 degrees to lay down the number of swing stop should be at least 70 times.
Fourth, the BM-3 pendulum coefficient of friction tester apparatus main part of the swing part of the rack part.
1,2 - tighten the handle; 3 - Lifting the handle; 4 - Release the switch; 5 - knuckle screw cap; 6 - adjusting nut; - needle reed or Felt
8 - pointer; 9 - connecting nut; 10 - leveling bolt; 11 - base; 12 - hinge; 13 - bubble level; 14 - clasp;
15 - positioning screws; 16 - Lifting the handle; 17 - counterweight; 18 - and tighten the nut; 19 - slippery block; 20 - rubber sheets; 21 - Anti-slip screw
1,: by the T-leg leveling screws and bubble level. Tone from the instrument level, supporting role.
2, column: column, the lifting mechanism, the guide bar and instrument handles. For the location of the lift and fixed Rocker.
3, release the switch: installed at the switch on the cantilever. Used to maintain the horizontal position and release of the pendulum to swing down the role.
4, the composition of the Rocker: by tightening the handle, the pendulum shaft, steering knuckles, bearings, etc., from the links placed, fixed position, to ensure free and swinging in the swing plane.
5, showing the number of system: consists of pointers, felt ring, flange, tighten the nut and the dial pointer directly indicates the coefficient of friction values.
6, the pendulum: the upper and lower joints, pendulum, spring, lever Department of lifting handle, shell, slippery block and sheet rubber composition. Its swing center of the required torque and the required pressure on the road itself before and after, left and right torque balance, which is a measure road surface friction coefficient of the scale.
BM-3 pendulum coefficient of friction tester test procedure
1, the choice of site: scooter direction in the test sections, the revolver round track, select a representative of five points, each measuring point a distance of about 5 ~ 10m from the pavement edge should not be less than 1m.
2, instrument leveling:
The instrument placed in the measuring point and the pendulum swing direction and the directions of traffic.
② Turn the leveling screws and bubble level center.
3, zero:
(1) relax the fixed handle, turn the lift handle, so put the rise and can swing freely, then tighten the handle.
(2) will be placed to the right movement, press the release switch. Release the clasp into the switch slot, and in the horizontal release position, then release the switch is released, the pointer should be released to close to dial the pin piece.
(3) press release switch, swing to the left movement, and promote the pointer upward movement, when placed to achieve the maximum home after the whereabouts of the pendulum with his left hand to catch the pointer should refer to zero. If not refer to zero, the adjusting nut slightly tighten or relax the felt circle. Repeat this operation until the pointer refers to zero.
4, calibration slide length:
(1) with a brush to remove loose particles and debris on the road in the swing range
(2) to put the free-hanging, outside swing parallel to the direction of the rubber sheet to set the standard foot (126mm) to relax the tightening handle, turn the lift handle. The pendulum slowly decline, when new to the road of the rubber sheet on the slippery block, to lift the lifting handle the slippery block increased, the pendulum moves to the right and turn the lift handle to put down some distance, and then put down the lifting handle to put slowly move to the left until the edge of the rubber sheet is just exposure to the road, one end is 126mm foot, and then hand to lift the lifting handle, and the slippery block lifted up and placed to continue to move to the left, put down the lift handle, then put the slowly moving to the right edge of the rubber piece once again contact with the road. Rubber sheet twice the distance of the point of contact with the road surface should be 126mm (slip length). Do not meet the 126mm rotating lifting handle, and then repeat the above steps for the coarse. In line with 126mm after tighten the fastening handle, and then corrected again, slide the length does not meet the standard, raise or lower the front of the instrument base leveling screws to correct, but to be leveling bubble level. Sliding length to meet the requirements. Thereafter, will be placed in a horizontal release position.
Measured: water poured the pavement, scraping with a rubber brush to wash away the mud, and then watering and press the release switch, placed on the road over the pointer to indicate the road surface friction coefficient (typically the first time to record). Catch the pendulum when the pendulum to swing back, with his left hand, right hand lift the lifting handle the slippery block increases, the movement of the pendulum to the right and press the switch, put a long loop into the release switch, and put the needle allocated to tight rely on dial-pin piece, repeat the determination of five (in each case the sprinkler), a record of each value. Five values ??not more than three units (instantly dial a cell half) the difference is greater than three units, you should check the causes, and repeat the above operation, to meet the provisions of the requirements so far.
6, determination of results:
(1) each measuring point with the friction coefficient of five determination of the average of the readings on behalf of the measuring point, and the friction coefficient of the average of five points, on behalf of the determination of sections of the friction coefficient.
(2) determination of reading, that is, the pointer on the dial readings (the "put value"), divided by 100 is the road friction coefficient. : Put the value 33, the friction coefficient is 0.33.
7, BM-3 pendulum coefficient of friction tester note:
(1) due to the road surface friction coefficient is influenced by the effects of season and temperature, it should record the test date and the temperature of the wet pavement.
(2) The test sections should describe the type of pavement structure, appearance and useful life.
(3) When the return swing to the left swing, be sure to hand to catch the pendulum in order to avoid damage to the slippery blocks and pointer.
(4) should not be within the effective range of rubber sheet sliding on the slippery block of convex and concave, so as not to affect the measured values.
(5) Calibration slide the length should be just a rubber sheet contact with the road shall not be by the power of the pendulum slide forward, slide length is too long to avoid calibration.
(6) the friction coefficient changes along the cross-section of the highway. Usually primary and secondary road, roadside. Should be selected to reflect the most unfavorable conditions of the test sections of the friction coefficient is small, more frequent brake position. Along the directions of traffic revolver wheel track at.
(7) on the slippery block, rubber films, should be tested on a dry road several times before. The long edge of sheet rubber abrasion shall not exceed 3.2mm, and the short side shall not exceed 1.6mm (see Figure 2). Otherwise they should be replaced with new rubber sheet. In addition, the rubber sheet for Oil Pollution. The effective use of rubber sheet for one year. A year later, regardless of whether the use, shall make the determination to use. Rubber aging, elasticity, hardness change, and affect the test results.
Figure 2, the maximum wear of the rubber sheet degrees
Six, annex
a) the watering can (a);
b) the rubber sheet (four);
c) standard ruler (a);
d) The rubber brush (a);
e) tripod (a);
VII Appendix
BM-3 tilting friction coefficient of determination of the calibration of the instrument tilting instrument:
1, the weight of the pendulum - relax the connecting nut of the pendulum rod and steering knuckle, remove from the instrument equipped with a slippery swing. Weighed accuray to g, (should be consistent with the 1500g ± 30g).
2, center of gravity - equipped with a slippery block placed center of gravity is determined by the location will be put placed on the knife-edge. Equilibrium point of the test position, connecting nuts, should be fixed on the arm remote to get the balance point, precession or spin out of balance hammer until the pendulum shell edge level and balance position to make a mark.
3, the distance from the swing center to center of gravity - the pendulum re-installed in the instrument and remove the screw cap of the steering knuckle. The distance measured from the swing center (bearing nut center) to the center of gravity, accurate to the mm (410mm ± mm) should be consistent. If differences in the center of gravity placed on the blade to change the torque adjustment nut position, necessary, increase or decrease the torque adjustment nut number, but shall comply with the requirements of (1) and (3), so that the pendulum balance meet the torque requirements.
4, the pressure calibration:
(1) will be placed from the instrument to remove the slippery block of rubber sheet and put the shell weeks board parallel. Ensure that the slippery block around its own axis of rotation, the shaft runout is greater than 0.2mm.
(2) the pressure calibration of the balance placed in the test stand, leveling so that the pointer refers to. Tripod placed on the right side of the rear of said disk. Pendulum instrument on the tripod on the folder block the pendulum on the column, so that the rubber sheet at the right, said disk Ministry and pressure 3 ~ 5mm, said disk plus 1g weight on the left, the balance stability (this when the balance pointer to the right side). Adjust the instrument base leveling screws so that the pointer to align the right side of 20mm, and pay attention to maintaining the standard foam center.
(3) in the left side of the pan and then add the calibration weight (2263g), the pointer should return to zero. Remove the calibration of the pendulum, insert the spring lead tank with a screwdriver, tighten or unscrew the spring tension adjustment nut so that the pointer back to zero. You should pay attention to grip the pendulum, tighten and relax regulator section nut Buzhi Yu artificial symmetry disk load. Then, re-checking the pressure, until the center of the pointer until the weight is coupled with calibration. (You can use the electronic scale calibration)