Please select the most similar patent number from A, B, C and D. Which number is?
A combined roller apparatus, comprising a basic roller (1) and at least one adjustable roller (2). The basic roller (1) and the adjustable roller (2) are both mounted on a center shaft (3). The adjustable roller (2) is mounted on a side face of the basic roller (1) and can be close to or distant from the basic roller (1). An adjustable working face (21) is provided on the adjustable roller (2). A basic working face (11) is provided on the basic roller (1). The adjustable working face (21) works in conjunction with the basic working face (11) to achieve continuous material forming work. The combined roller apparatus can produce products of different specifications in a production line without roller replacement.
A: A twist drill for smart home processing. The twist drill comprises an adjustable portion (2), wherein a mounting portion (1) is formed at one end of the adjustable portion (2), and a working portion (3) is fixed to the other end thereof, the adjustable portion (2) comprises an adjustable cavity with an open end close to the working portion (3), an adjustable mechanism (21) is fixed to the end inside the adjustable cavity that is close to the mounting portion (1), and a shock absorption mechanism (23) is fixed to the end thereof close to the working portion (3). The length adjustment function of the twist drill in use can be achieved by means of the adjustable mechanism (21), such that the application range of the twist drill is expanded. The vibration amplitude of the working portion (3) can be effectively reduced by means of the shock absorption mechanism (23), thereby preventing a drill bit from breaking due to large vibration amplitude, and also improving stability and precision of the drill bit during working.
B: An extrusion roller device and rolling mill equipment, the extrusion roller device comprising: a moving extrusion roller (20) and a rotating shaft (10), the rotating shaft comprising an eccentric shaft segment (11), and the moving extrusion roller comprising a left extrusion roller (21) and a right extrusion roller (22); the left extrusion roller is axially fixedly mounted on a left mounting shaft (111) of the eccentric shaft segment, while the right extrusion roller is arranged opposite to the left extrusion roller and is axially fixedly mounted on a right mounting shaft (112) of the eccentric shaft segment; the axis of the left mounting shaft and the axis of the right mounting shaft are parallel and do not overlap; when the rotating shaft rotates, the left extrusion roller and the right extrusion roller rotate synchronously with the eccentric shaft segment to form a left and a right extrusion surface having a height difference. By means of mounting the left extrusion roller and the right extrusion roller of the moving extrusion roller on the eccentric shaft segment of the rotating shaft respectively, when the rotating shaft rotates, the outer diameters of the extrusion surfaces of the two extrusion rollers may generate different height differences at different positions such that the working position of the extrusion rollers may be adjusted, while the phenomenon of bending deformation of the rotating shaft is reduced, thus increasing the precision of extrusion work.
C: An adjustable welding tooling for a plastic packaging IPM, comprising a substrate (1), wherein a first groove (2) for accommodating a PCB board (4) and a second groove (3) for accommodating a DBC board (5) are arranged on the substrate (1), the depth of the second groove (3) being greater than the depth of the first groove (2); and a slide block (6) is arranged at the bottom of the second groove (3), and the slide block (6) is adjustable in a longitudinal position in the second groove (3). The slide block (6) is arranged at the bottom of the second groove (3), and the slide block (6) is adjustable in the longitudinal position in the second groove (3), so that the longitudinal position of the DBC board (5) placed in the second groove (3) can be adjusted during the usage process, so as to complete brushing a solder paste onto the surfaces of a PCB board (4) and a DBC board (5) and complete the assembly with a wire frame without changing the tooling, so that a tooling device is saved, the work efficiency is improved, and the qualified rate of finished products is further improved.
D: A drilling and bursting heading machine, comprising a drilling and bursting device (1), an angle control device, a forward-backward telescopic device, and a cantilever type heading machine (2). The drilling and bursting device (1) is mounted on a forward-backward moving component of the forward-backward telescopic device by means of the angle control device; the forward-backward telescopic device is mounted on the cantilever type heading machine (2); the drilling and bursting device (1) comprises a fixing support (1-20), as well as a rock drilling component and a bursting component fixedly mounted on the fixing support (1-20); the angle control device comprises a mounting base (1-15), an auxiliary rotary hydraulic motor (1-14), an adjustment hydraulic cylinder (1-13), and a main rotary hydraulic motor (1-12); when the forward-backward moving component of the forward-backward telescopic device completely extends out, a distance from a front end of the drilling and bursting device (1) to a working plane is less than a distance from a front end of a cutting head of the cantilever type heading machine (2) to the working plane. The drilling and bursting heading machine has a compact structure and is able to quickly implement punching and bursting on a hard rock stratum having a rock hardness greater than 10 without increasing the power consumption, so that the heading efficiency is improved and potential safety risks are reduced.
Answer: B